Forces & Newton’s Laws MC Practice...

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Forces & Newton’s Laws MC Practice Questions 1) Which of Newton’s laws describes equilibrium? a) The first, which mathematically states that Σ F = 0. b) The second, which mathematically states that Σ F = ma. c) The third, which mathematically states that F = -F. d) The fourth, which mathematically states that Σ F = Gm 1 m 2 /r 2 . e) The fifth, which mathematically states that dx/dt = v. 2) If all of the forces acting on an object balance so that the net force is zero, then a) the object must be at at rest b) the object’s speed will increase c) the object’s direction of motion can change, but not its speed d) None of the above will occur. 3) Object A, when acted upon by a force F, accelerates at a rate of 4.0 m/s/s. The same force accelerates Object B at a rate of 8.0 m/s/s. Compared to the mass of Object A, the mass of Object B is: a) Four times as great b) Twice as great c) The same d) One-half as great e) One-fourth as great

Transcript of Forces & Newton’s Laws MC Practice...

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Forces & Newton’s Laws MC Practice Questions  1) Which of Newton’s laws describes equilibrium?

a) The first, which mathematically states that Σ F = 0. b) The second, which mathematically states that Σ F = ma. c) The third, which mathematically states that F = -F. d) The fourth, which mathematically states that Σ F = Gm1m2/r2. e) The fifth, which mathematically states that dx/dt = v.  2) If all of the forces acting on an object balance so that the net force is zero, then

a) the object must be at at rest b) the object’s speed will increase c) the object’s direction of motion can change, but not its speed d) None of the above will occur.  3) Object A, when acted upon by a force F, accelerates at a rate of 4.0 m/s/s. The same force accelerates Object B at a rate of 8.0 m/s/s. Compared to the mass of Object A, the mass of Object B is:

a) Four times as great b) Twice as great c) The same d) One-half as great e) One-fourth as great

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Forces & Newton’s Laws MC Practice Questions  4) An object is supported by a spring attached to the ceiling. What are the forces acting on the object? a) The mass of the object in the downward direction and the supporting force of the spring in the upward direction b) The mass of the object in the downward direction and the supporting force of the spring in the downward direction c) The weight of the object in the upward direction and the supporting force of the spring in the downward direction d) The weight of the object in the downward direction and the supporting force of the spring in the upward direction e) The weight of the object pulling on the Earth and the downward supporting force of the spring  5) Rank the following scenarios from the greatest to the smallest acceleration:

I. Net force F applied to mass M II. Net force 2F applied to mass M III. Net force F applied to mass 2M IV. Net force 2F applied to mass 2M

a) II > I = IV > III b) I > II > III > IV c) III > IV = I > II d) IV > II > III > I e) III > I = II > IV

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Forces & Newton’s Laws MC Practice Questions  6) Two forces are applied to a body initially at rest on a frictionless surface as shown below. Rank the diagrams from the largest acceleration to the least.

a) B > D > A > C b) B > A = C > D c) C > A > B > D d) C > B > A > D  

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Forces & Newton’s Laws MC Practice Questions  7) A body weighing 49 N is lifted by a cord as shown in the diagram below. What acceleration does the body experience?

a) 6.0 m/s2 b) 5.0 m/s2 c) 1.2 m/s2 d) 0.83 m/s2  Multi-select: For questions 38-41, two of the suggested answers will be correct. Select the two best answers, and circle both. 8) A book is resting on a table. Which of the following forces act on the book? a) The gravitational force b) The of the book on the table c) The supporting force of the table on the book d) The net downward force of air on the book e) The force of the table on the floor

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Forces & Newton’s Laws MC Practice Questions  9) Consider the forces on a child standing in an elevator. When is the normal force from the elevator equal to the gravitational force? a) When the elevator moves upward at a constant speed b) When the elevator accelerates upward c) When the elevator is at rest d) When the elevator accelerates downward at a constant rate e) When the child is jumping off the floor of the elevator  10) A person standing on a horizontal floor feels two forces: the downward pull of gravity and the upward supporting force from the floor. These two forces

a) have equal magnitudes and form an action/reaction pair b) have equal magnitudes and do not form an action/reaction pair c) have unequal magnitudes and form an action/reaction pair d) have unequal magnitudes and do not form an action/reaction pair

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Forces & Newton’s Laws MC Practice Questions  11) A person who weighs 800 N steps onto a scale that is on the floor of an elevator car. If the elevator accelerates upward at a rate of 5 m/s2, what will the scale read? a) 400 N b) 800 N c) 1000 N d) 1200 N 12) This position-time graph is typical of which type of motion?

a) Motion of an object with an increasing net force acting upon it. b) Motion with zero velocity. c) Motion of an object with an increasing net force acting upon it. d) Motion of an object with no net force acting upon it. e) Motion of an object with negative net force acting upon it.

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Forces & Newton’s Laws MC Practice Questions  13) An object’s position with time is depicted in this graph. At which time range will there be nearly no net force acting on the object?

a) 0.5 to 1.0 s b) 1.0 to 1.5 s c) 1.8 to 2.2 s d) 2.5 to 3.0 s

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Forces & Newton’s Laws MC Practice Questions  14) This graph depicts the velocity of a skydiver over time during free-fall. Which of the following statements is true?

a) The net forces acting on the skydiver increase until the acceleration reaches its maximum and the velocity becomes constant. b) The net forces acting on the skydiver decrease until the acceleration reaches zero and the velocity becomes constant. c) There are no net forces acting on the skydiver. d) The net forces acting on the skydiver increase until the acceleration reaches zero and the velocity becomes constant. e) The net forces acting on the skydiver decrease until the acceleration reaches zero and the velocity becomes zero.

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Forces & Newton’s Laws MC Practice Questions  15) A boy is pushing a 50 kg crate across a frictionless surface. The velocity is changing with time as shown in this graph. What is the magnitude of the force that the boy applies to the crate?

a) 5 N b) 10 N c) 15 N d) 20 N e) 25 N

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Forces & Newton’s Laws MC Practice Questions  16) A 1.80 kg body experiences a force acting on it for 5.00s. The graph representing the velocity of the body vs. time is given below.

What was the magnitude of the force?

a) 5.40 N b) 3.00 N c) 1.50 N d) 0.60 N

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Forces & Newton’s Laws MC Practice Questions  17) The acceleration-time graph of an object’s motion is shown in this figure. At what time will the forces acting on it be balanced?

a) 0 s b) 1 s c) 2 s d) 3 s e) 4 s

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Forces & Newton’s Laws MC Practice Questions  18) The acceleration of a 5 kg object over time is shown in this graph. What is the net force at 1 s?

a) -10 N b) -5 N c) -2.5 N d) 5 e) 10 N 19) Two boys push a 5 kg box on a frictionless floor. James pushes the box with a 10 N force to the right. Louis pushes the box with an 8 N force to the left. What is the magnitude and direction of the box’s acceleration? a) 0 m/s2; the box does not move b) 0.4 m/s2 to the right c) 0.4 m/s2 to the left d) 1.6 m/s2 to the right e) 1.6 m/s2 to the left

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Forces & Newton’s Laws MC Practice Questions  20) Only two forces act on a 0.1 kg object. This graph depicts the magnitudes and directions of only those two forces. What is the acceleration of the object at the 2 s clock reading?

a) 0 m/s2 b) 0.2 m/s2 c) 1.0 m/s2 d) 2.0 m/s2 e) 4.0 m/s2

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Forces & Newton’s Laws MC Practice Questions  21) You pull straight down on one side of a rope stretched across a pulley. Attached to the other side of the rope is a 10 kg box. How much force must you pull down on the rope to the get the box to accelerate upward at a rate of 10 m/s2?

a) 10 N b) 20 N c) 100 N d) 150 N e) 200 N

22) A 5.00 kg body is supported by a single cord that hangs from the ceiling of a room. The tension in the cord is

a) 5.00 kg b) 5.00 N c) 49.0 kg d) 49.0 N

23) A six-strand vertical pulley is used to raise a load with a mass of 1,000 kg. The tension on the pulley cables is closest to which of the following?

a) 15,000 N b) 1,000 N c) 1,600 N d) 10,000 N e) 170 N

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Forces & Newton’s Laws MC Practice Questions  24) A person stands on a bathroom scale in an elevator moving downward with an acceleration of -2.00 m/s2. The bathroom scale will read a) the true weight of the person b) a weight larger than the true weight of the person c) a weight smaller than the true weight of the person d) a fractional change in the true weight, but since the true weight is not given, there is no way to determine it 25) A soldier fires a musket with a barrel that is 1 m in length. The gases from the exploding gunpowder exert a net force of 50 N on a 0.010 kg bullet as it travels through the musket barrel. What is the bullet’s velocity as it leaves the musket barrel? a) 10 m/s b) 100 m/s c) 1,000 m/s d) 10,000 m/s e) 100,000 m/s

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Forces & Newton’s Laws MC Practice Questions  26) A 3 kg mass is moving at 6 m/s is brought to rest in 2 s. The magnitude of the force acting on the mass it

a) 18 N b) 9 N c) 6 N d) 12 N e) 36 N 27) A car with a mass of 1,000 kg travels at 30 m/s. The driver applies his brakes for a uniform deceleration and comes to a complete stop in 60 m. Assuming that the forward motion is positive, what is the magnitude and direction of the net force acting on the car? a) 7,500 N b) 5,000 N c) -1,000 N d) -5,000 N e) -7,500 N

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Forces & Newton’s Laws MC Practice Questions  28) A bowler applies a constant net force of 100 N on a 5 kg bowling ball over a time period of 1.5 s before he releases the ball. The ball starts from rest. What is its final velocity? a) 5 m/s b) 10 m/s c) 20 m/s d) 30 m/s e) 40 m/s 29) A jet flies at level flight. The engines produce a total of 20,000 N of forward thrust, the jet’s mass is 50,000 kg, and it accelerates at 0.3 m/s2. What is the magnitude of the air resistance against which the jet flies?

a) 1,000 N b) 3,000 N c) 5,000 N d) 10,000 N e) 15,000 N    

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Forces & Newton’s Laws MC Practice Questions  30) A girl pushes a 10 kg box from rest across a horizontal floor with a force of 50 N. The force of friction opposing her is 45 N. If the box uniformly accelerates from rest to a final velocity of 2.0 m/s, how much time did it take to reach that velocity? a) 1 s b) 2 s c) 3 s d) 4 s e) 5 s 31) A rocket goes from rest to 9.6 km/s in 8 min. The rocket’s mass is 8.0 x 106 kg. Assuming a constant acceleration, what is the net force acting on the rocket? a) 1.6 x 105 N b) 9.6 x 105 N c) 9.6 x 106 N d) 1.0 x 107 N e) 1.6 x 108 N

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Forces & Newton’s Laws MC Practice Questions  32) A car travels at a constant velocity of 30 m/s. The mass of the car is 1,000 kg. The forward force of the road on the car is 1,000 N. What is the total amount of backward force on the car from air drag and rolling friction? a) 1,000 N b) 10,000 N c) 9,000 N d) 3,000 N e) 2,000 N 33) A 1,000 kg car is initially traveling at 30 m/s. The driver applies the brakes suddenly, and the friction from the road exerts 9,000 N of force on the car. If the car uniformly decelerates to a complete stop, how far does the car travel during the braking process? a) 2m b) 50 m c) 100 m d) 200 m e) 450 m

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Forces & Newton’s Laws MC Practice Questions  34) At the very beginning of a dash, a 70 kg runner acceleratess uniformly from rest to 10 m/s in 0.5 s as she moves in the positive direction. What is the net force acting upon the runner?

a) -7,000 N b) -1,400 N c) 0 N d) 1,400 N e) 7,000 N 35) A jet takes off at an angle of 60° to the horizontal. The jet flies against a wind that exerts a horizontal force of 1,000 N on it. The engines produce 20,000 N of thrust (60° to the the horizontal), and the mass of the jet is 90,000 kg. What is the rate of the jet’s acceleration in the horizontal direction? a) 0.1 m/s2 b) 0.2 m/s2 c) 1.0 m/s2 d) 5.0 m/s2 e) 10 m/s2

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Forces & Newton’s Laws MC Practice Questions  36) A rope is strung between two cliffs. A mountain climber weighing 100 kg is halfway across the rope when the rope forms an angle of 45° with the horizontal. The tension in the rope is closest to what value? (Assume the gravitational field strength is 10 N/kg.) a) 1000 N b) 500 N c) 700 N d) 250 N e) 100 N 37) In the situation shown below, what is the tension in string 1?

a) 69. 3 N b) 98 N c) 138.6 N d) 147.6 N e) 155 N

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Forces & Newton’s Laws MC Practice Questions  

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Forces & Newton’s Laws MC Practice Questions  38) A box slides to the right along a horizontal surface. Which is true about the friction force? a) It acts perpendicular to the surface. b) It is a force in the direction of motion that allows the bow to move. c) It is a force that is proportional to the normal force that acts opposite to the direction of motion. d) It is a force that is proportional to the normal force that acts in the direction of motion. e) It is a force that is proportional to the square of the object’s weight and acts in the direction of motion.

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Forces & Newton’s Laws MC Practice Questions  

39) A rope applies 35 N of force, as shown in the figure. As a result, the box accelerates to the left along the surface. In addition to the gravitational force, which of the following forces act on the box? a) The downward force of the box on the table b) The frictional force of the surface on the box c) The upward force of the table on the box d) The force of motion to the left on the box e) The tension force of the rope on the box

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Forces & Newton’s Laws MC Practice Questions  

40) A weight W is pulled by a rope at an angle θ across a horizontal surface where the coefficient of kinetic friction is µ. Which of the following is true for the friction force f acting on the mass?

a) f = µW b) f = µ(W + Fsinθ) c) f = µ(W + Fcosθ) d) f = µ(W – Fsinθ) e) f ≤ µ(W – Fcosθ)  

41) When F = 8 N, the 4 kg mass accelerates to the right at 1 m/s2. If F is doubled to 16 N, the acceleration will be

a) 1 m/s2 b) 2 m/s2 c) 3 m/s2 d) 4 m/s2 e) 0.5 m/s2

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Forces & Newton’s Laws MC Practice Questions  42) A boy pushes a 10 kg crate across the floor with a constant force of 10 N against a force of friction. The box accelerates at a rate of 0.1 m/s2. What is the magnitude of the opposing frictional force? a) 0 N b) 1 N c) 5 N d) 9 N e) 10 N 43) A hockey puck with a mass of 0.3 kg is sliding along ice that can be considered frictionless. The puck’s velocity is 20 m/s. The puck now crosses over onto a floor that has a coefficient of kinetic friction equal to 0.35. How far will the puck travel across the floor before it stops? a) 3m b) 87 m c) 48 m d) 92 m e) 58 m

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Forces & Newton’s Laws MC Practice Questions  44) A 2.00 kg body is pulled along a rough horizontal surface, µ = 0.20, by a 10.0 N force acting at an angle of 40° with the horizntal. Which of the following diagrams correctly illustrates the forces acting on the body?

a) I b) II c) III d) IV 45) Using the information from the previous problem, the acceleration of the 2.00 kg body is closest to a) 1.85 m/s2 b) 2.50 m/s2 c) 2.75 m/s2 d) 3.80 m/s2

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Forces & Newton’s Laws MC Practice Questions  46) A 20 N block is being pushed across a horizontal table by an 18 N force. If the coefficient of kinetic friction between the block and the table is 0.4, find the acceleration of the block.

a) 0.5 m/s2 b) 1 m/s2 c) 5 m/s2 d) 7.5 m/s2 47) A crate of mass 100 kg is at rest on a horizontal floor. The coefficient of static friction between the crate and the floor is 0.4, and the coefficient of kinetic friction is 0.3. A force F of magnitude 344 N is then applied to the crate, parallel to the floor. Which of the following is true?

a) The crate will accelerate across the floor at 0.5 m/s2. b) The static friction force, which is the reaction force to F as guaranteed by Newton’s 3rd, will also have a magnitude of 344 N. c) The crate will slide across the floor at a constant speed of 0.5 m/s. d) The crate will not move.

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Forces & Newton’s Laws MC Practice Questions  48) A box that is resting on an inclined plane has what forces acting on it? a) The weight of the box, the box’s component forces perpendicular to and along the plane, and the friction force along the surface of the plane beneath the box b) The weight of the box, the box’s component forces perpendicular to and along the plane, the resultant force of the plane on the box, and the friction force along the surface of the plane beneath the box c) The weight of the box and the friction force along the surface of the plane beneath the box d) The mass of the box and its acceleration along the plane e) The weight of the box, the perpendicular force of the plane on the box, and the friction force along the surface of the plane beneath the box

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Forces & Newton’s Laws MC Practice Questions  49) A 2.00 kg body accelerates down a 30° inclined plane where the coefficient of friction between the body and the plane is small. Increasing the a) angle of the inclined plane makes with the horizontal will increase the effective weight down the plane and thus the acceleration down the plane will increase b) mass of the body will increase the acceleration since it increases the effective weight down the plane c) angle will have no effect on the acceleration down the plane since it will not change the net force on the body d) mass will not change the acceleration

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Forces & Newton’s Laws MC Practice Questions  50) A student makes a free-body diagram of an object accelerating down an inclined plane as shown below.

a) The normal to the surface is not vertical and opposite to the weight, but is perpendicular to the surface. b) Friction opposes the motion and should be directed down the plane. c) An arrow showing the acceleration down the plane is incorrect, since acceleration is not a force. d) All forces are shown correctly in the diagram. There are no mistakes.          

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Forces & Newton’s Laws MC Practice Questions  51) A box of unknown mass (m) slides down a plane inclined at an angle (θ). The plane has a coefficient of friction (µ). Which of the following expressions would you use to calculate the rate of acceleration (a)?

a) a = g(sinθ - µgcosθ)/m b) a = g(cosθ - µgsinθ)/m c) a = m(sinθ - µgcosθ)/g d) a = g(sinθ - µcosθ) e) a = g(cosθ - µsinθ) 52) The coefficient of static friction between a box and a ramp is 0.5. The ramp’s angle of incline is 30°. If the box is placed at rest on the ramp, the box will

a) Accelerate down the ramp. b) Accelerate briefly down the ramp but then slow down and stop. c) Move with a constant speed down the ramp. d) Not move.

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Forces & Newton’s Laws MC Practice Questions  53) A frictionless inclined plane of length 20 m has a maximum vertical height of 5 m. If an object of mass 2 kg is placed on the plane, which of the following best approximates the net force it feels.

a) 5 N b) 10 N c) 15 N d) 20 N 54) A 12 kg mass is at rest on a 30 incline where the coefficient of static friction is 0.8. The friction force exerted on the mass is most nearly

a) 120 N b) 104 N c) 83 N d) 60 N e) 96 N

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Forces & Newton’s Laws MC Practice Questions  55) A large 2,000 N cement block is pulled constantly up a frictionless 43° incline using a dual-strand pulley that is attached to the block. One end of the rope is tied to the wall at the top of the plane while a man is pulling the other end of the rope. What is the tension in the rope if it is pulled parallel to the plane? a) 732 N b) 682 N c) 1,463 N d) 1,364 N e) 462 N 56) A 100 kg box is sitting on a 10° incline with a coefficient of friction of 0.5. At what angle must the incline be raised to start sliding the box? a) 30° b) 33° c) 27° d) 24° e) 15°

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Forces & Newton’s Laws MC Practice Questions  57) A 10 kg crate is on a plane that is inclined at an angle of 45°. The coefficient of friction is 0.1, and the downward direction is positive. What is the approximate rate of the box’s acceleration? a) 0 m/s2 b) 4.2 m/s2 c) 6.4 m/s2 d) 8.7 m/s2 e) 10.0 m/s2 58) A skier with a mass of 70 kg pushes off from the top of a ski slope with a force of 105 N directed down the slope. The slope is inclined at 30°. Assuming that the slope is frictionless, what is the initial rate of the skier’s acceleration during the push-off?

a) 0.5 m/s2 b) 1.0 m/s2 c) 2.0 m/s2 d) 7.0 m/s2 e) 11.0 m/s2

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Forces & Newton’s Laws MC Practice Questions  59) A mass, M, is released from rest on an incline that makes a 42° angle with the horizontal. In 3 s, the mass is observed to have gone a distance of 3 m. What is the coefficient of kinetic friction between the mass and the surface of the incline?

a) 0.8 b) 0.7 c) 0.6 d) 0.5 e) 0.3

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Forces & Newton’s Laws MC Practice Questions  60) A tow truck is pulling a car out of a ditch. Which of the following statements is true about the forces between the truck and the car? a) The force of the truck on the car is greater than the force of the car on the truck. b) The force of the truck on the car is less than the force of the car on the truck. c) The force of the truck on the car is equal in magnitude to the force of the car on the truck. d) The force of the truck on the car may be equal to the force of the car on the truck, but only when the system is in a state of constant velocity. e) The force of the truck on the car may be greater than the force of the car on the truck, but only when the system is accelerating.

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Forces & Newton’s Laws MC Practice Questions  61) Two blocks are pushed across a frictionless surface by a constant horizontal force as shown in the diagram below.

The mass of block A is m and the mass of block B is 2m. If the blocks remain in contact as they move across the surface, block B experiences a net force of a) 2F/3 b) F c) 3F/2 d) 2F

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Forces & Newton’s Laws MC Practice Questions  62) A 20 N force is pushing two blocks horizontally across a frictionless floor as shown below.

What is the force that the 8 kg mass exerts on the 2 kg mass?

a) 4 N b) 8 N c) 16 N d) 20 N e) 24 N

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Forces & Newton’s Laws MC Practice Questions  63) Two bodies connected by a massless rod as shown in the diagram are moving with some velocity to the right on a frictionless surface.

An external force is applied to the bodies as shown:

The applied force will: a) have no effect on the velocity of center of mass of the system since it is only applied to the larger body b) increase the velocity of the center of mass of the system since will provide an acceleration to the system c) only change the velocity of the larger body d) maintain the initial velocity as a constant since forces would have to be applied to both bodies in order to increase the velocity of the center of mass

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Forces & Newton’s Laws MC Practice Questions      

64) A tension T exists in the rope connecting the two masses. The value of F is

a) 3T/2 b) 3T/5 c) T d) 5T/3 e) 5T/2 65) Two crates are stacked on top of each other on a horizontal floor; Crate 1 is on the bottom, and Crate 2 is on top. Both crates have the same amount of mass. Compared to the strength of the force F1 necessary to push only Crate 1 at a constant speed across the floor, the strength of the force F2 necessary to push the stack at the same constant speed across the floor is greater than F1 because

a) the normal force on Crate 1 is greater b) the coefficient of kinetic friction between Crate 1 and the floor is greater c) the coefficient of kinetic friction between Crate 1 and the floor is less d) the weight of Crate 1 is greater

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Forces & Newton’s Laws MC Practice Questions  66) A diagram showing the forces acting in a system is illustrated below. Consider the pulley to be an ideal pulley. Ignore friction and air resistance.

Which of the four choices gives the correct mathematical expression for the representation of the system? a) T2 – T1 = ma b) T2 – T1 = (m1 + m2)a c) m2g – m1g = (m1 – m2)a d) m2g – m1g = (m1 + m2)a    

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Forces & Newton’s Laws MC Practice Questions  67) Two masses, M and m, are hung over a frictionless pulley as shown below. If M > m, what is the downward acceleration of mass M?

a) g b) (M – m)g / (M + m) c) (M/m)g d) Mmg / (M+ m) e) Mmg  

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Forces & Newton’s Laws MC Practice Questions  

68) Assuming a frictionless, massless pulley, determine the acceleration of the blocks once they are released from rest.

a) mg /(M + m) b) Mg/m c) (M + m)g/(M – m) d) (M – m)g/(M + m)

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Forces & Newton’s Laws MC Practice Questions  69) Two masses are hanging vertically by a rope strung through a pulley. The mass on the left of the pulley is 5 kg, while the mass on the right is 10 kg. What is the magnitude and direction of the 10 kg mass’ acceleration? a) 0 m/s2 b) -3.3 m/s2 c) -5.0 m/s2 d) 3.3 m/s2 e) 5.0 m/s2  70) A block with a mass of 30 kg is located on a horizontal, frictionless tabletop. This block is connected by a rope to another block with a mass of 10 kg. The rope is looped through a pulley on the table’s edge so that the less massive block is hanging over the edge. What is the magnitude of the larger block’s acceleration across the table? a) 0.5 m/s2 b) 1.2 m/s2 c) 2.5 m/s2 d) 3.5 m/s2 e) 4.0 m/s2        

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Forces & Newton’s Laws MC Practice Questions  71) According to the diagram below, what is the tension in the connecting string if the table is frictionless?

a) 6.4 N b) 13 N c) 20 N d) 25 N e) 32 N                                

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Forces & Newton’s Laws MC Practice Questions  72) A 20.0 N force is applied to the bodies in the diagram below. Consider the contact surfaces to be frictionless and ignore air resistance.

The magnitude of the acceleration of the masses indicates a) a2kg > a1kg b) a2kg < a1kg c) a2kg = a1kg d) the only acceleration is a2kg                        

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Forces & Newton’s Laws MC Practice Questions  73) A 2.00 kg block is connected to a 1.00 kg block by a massless cord that passes over an ideal pulley, as shown in the diagram below. (Neglect frictional forces.)

When the 1.00 kg body strikes the floor, the speed of the center of mass of the system is closest to a) 3.67 m/s b) 3.13 m/s c) 2.21 m/s d) 1.81 m/s              

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Forces & Newton’s Laws MC Practice Questions    

74) Assuming no friction, to double the current value of the system’s acceleration, you could

I. double the value of m2 II. halve the value of m1 III. halve the value of (m1 + m2) by adjusting m1 only

a) I only b) II only c) III only d) I and II e) I and III                      

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Forces & Newton’s Laws MC Practice Questions                                                                                            

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Forces & Newton’s Laws MC Practice Questions   75) A block of mass m is at rest on a frictionless, horizontal table placed in a laboratory on the surface of the Earth. An identical block is at rest on a frictionless, horizontal table placed in a ;laboratory on the surface of the Moon. Let (F) be the net force necessary give the Earth-bound block an acceleration of (a) across the table. Given that gMoon is one-sixth of gEarth, the force necessary to give the Moon-bound block the same acceleration (a) across the table is

a) F/6 b) F/3 c) F d) 6F  76) The acceleration due to gravity on a certain planet is approximately one-fourth of that on the surface of the Earth. What force is required to accelerate a 25.0 kg mass on the surface of the planet?

a) one-fourth of the force required on the surface of the Earth b) one-half of the force required on the surface of the Earth c) the same as the force required on the surface of the Earth d) four times the force required on the surface of the Earth

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Forces & Newton’s Laws MC Practice Questions    77) Which of the following are properties of mass?

a) Mass is the ratio of weight to volume b) Masses push on other masses c) A mass experiences an attractive force to another mass d) Mass is the amount of space something occupies e) Mass resists changes in motion    78) A student claims that two spheres of different mass dropped from rest above the surface of the Moon will hit the ground at the same time. Which of the following is a correct assessment of this statement?

a) The more passive sphere will hit the surface first because it’s heavier. b) Neither sphere will hit the surface because there is no gravity on the Moon and they will both float. c) The less massive sphere will hit the surface first because its smaller profile will hit more air, which will slow down its motion. d) They will hit the ground at approximately the same time because the net force-to-mass ration is the same for both. e) Physicists have no models to predict which sphere will hit first.