Slide 1

Conceptual Physics by HewittC H A P T E R 2-Linear Motion

http://www.youtube.com/watch?v=hz65AOjabtM

PowerPoint 2.8Acceleration Math ProblemsHow to mathematically solve kinematic problems that involve acceleration.

Average velocity if traveling in a straight line.

Vave = v

= d/t

= x/ t = (xf xi)/ (tf - ti )

AccelerationIf an object is moving in a straight line

Units of acceleration:Distance/ time = distance/time2 timem/s2= v /t = (vf vi)/(tf - ti)

Acceleration due to the force of gravity10 m/s2

Average velocity when acceleration is constant.

Equation with a, t, vi, and vf

Equation with d, vi, a and t

Equation with Vi, Vf, a, and d

Example 1. A car slows down at a constant rate from 100 km/hr to 30 km/hr in 10 seconds. What is the average velocity during this time?

What initial vertical velocity is a rock thrown down if its velocity 5 seconds after being thrown is 70 m/s?

How much time will it take a car to go down a 100-meter track from a stationary position if it accelerates at 10 km/hr every second?

If you throw a ball up with an initial velocity of 30 m/s, how high will the ball go?

What is the initial velocity of a ball thrown in the air if it reaches a height of 2 meters?

More help ..http://www.bozemanscience.com/speed-velocity-acceleration http://www.khanacademy.org/science/physics/one-dimensional-motion

Go to next slideYour turn to solve a problem... If you dropped an egg from the top of the bleachers, which are 5 meters above the ground, at what velocity will it hit the ground?

Solve and send the answer to me (seibert-cindy@wc235.k12.il.us)

If you need help selecting the right equation, go to the next slide.

A common physics project is to design a device to protect an egg from breaking when dropped from an elevated platformUse Equation 5