Phys 11: chap 2, Pg 3phy21bio/Presentations/CH1.pdf3 Phys 11: chap 2, Pg 5 Phys 11: chap 2, Pg 6...
Transcript of Phys 11: chap 2, Pg 3phy21bio/Presentations/CH1.pdf3 Phys 11: chap 2, Pg 5 Phys 11: chap 2, Pg 6...
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Phys 11: chap 2, Pg 2
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Phys 11: chap 2, Pg 3
Phys 11: chap 2, Pg 4
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Phys 11: chap 2, Pg 5
Phys 11: chap 2, Pg 6
average speed = total distance traveled
total time
speed and velocity measure how position changes with time
t
x
Δ x
Δ t
trajectory
t1
x1
t2
x2
average velocity = displacement total time
x2 – x1 t2 – t1
= Δx Δt
=
formula for a slope!
vav = slope connecting line from t1 to t2
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Phys 11: chap 2, Pg 7
1) more than 40 mi/hr
2) equal to 40 mi/hr
3) less than 40 mi/hr
Phys 11: chap 2, Pg 8
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Phys 11: chap 2, Pg 9
The velocity at a specific instant of time
v(t2 ) = slope of line tangent to path at t2
Review: Average velocity between x1 and x2
t
x
Δ x
Δ t t1
x1
t2
x2
vav = Δx Δt
Take two times very close to each other so Δt is very small
t
x Δ x
Δ t
v = limit = Δt→0
Δx Δt
What is the velocity right at point x2 at the instant the time is t2
Inst
anta
neou
s Av
erag
e
dx dt
Phys 11: chap 2, Pg 10
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Phys 11: chap 2, Pg 11 moving along +x but slowing down
x-axis
Phys 11: chap 2, Pg 12
acceleration measures how the velocity changes with time
average acceleration = change in velocity total time
v2 – v1 t2 – t1
= Δv Δt
=
formula for a slope!
t
v
Δ v
Δ t t1
v1
t2
v2
Aver
age
slope → a
t
v
t
Inst
anta
neou
s
slope of tangent → a
a = limit = Δt→0
Δv Δt
dv dt
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Phys 11: chap 2, Pg 13
1. 1 2. 2 3. 3 4. 4
v
t 1
t 2
v
t 3 v
t 4
Phys 11: chap 2, Pg 14
v
t 1
v
t 2
v
t 3 v
t 4
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Phys 11: chap 2, Pg 15
1. Choice One 2. Choice Two 3. Choice Three 4. Choice Four
v
t 1
t 2
v
t 3 v
t 4
Phys 11: chap 2, Pg 16
v
t 1
v
t 2
v
t 3 v
t 4
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Phys 11: chap 2, Pg 17
1. Choice One 2. Choice Two 3. Choice Three 4. Choice Four
v
t 1
t 2
v
t 3 v
t 4
Phys 11: chap 2, Pg 18
v
t 1
v
t 2
v
t 3 v
t 4