Physics
2012
Name: _________________
UNIT 2
KINEMATICS REVIEW
Date: _______ Period:_____
1)
When you look at the speedometer in a moving car, you can see the car’s _____.
(A) instantaneous speed.
(B) average speed
(C) average acceleration
(D
) instantaneous acceleration
(E) average distance traveled
(F) instantaneous positi
on
2
)
A boat is traveling west with a constant velocity
of 33
m/s. Which of the following statements is true?
(A) The boat has a positive acceleration.
(B) The boat has a negative acceleration.
(C) The boat has zero
acceleration.
(D) The boat is not moving.
3
)
If a swimmer has to swim 5 laps of the pool (to the end and back), with one length of the pool being 50
meters,
what is the swimmer’s
distance and
displacement?
(A) 250m
, 250 m
(B) 500m
, 500m
(C)
500 m, 0m
(D) 500 m, 250m
4
)
A wallaby
, travelling north, has
a positive initial velocity and a negative acceleration
. Which of the following
best
describes
the motion of the wallaby?
(A) The wallaby has a constant speed.
(B)
The wallaby is speeding up.
(C) The wallaby is slowing down.
(D) The wallaby is travelling in a negative direction.
True or F
alse:
5
)
The rate at which distance is covered is called speed.
___
True
________
6
)
Average speed is defi
ned as the time it takes for a
trip divided by
the distance
travel
ed
.
_____
True
______
7
)
Velocity is different from speed in that velocity is speed
in a
given direction.
____
True
_______
8
)
The SI unit of velocity is the meter.
__
False m/s
_________
9
)
The SI unit of acceleration is m/s.
___
False m/
s
2
________
10)
The rate at which velocity changes with time is called acceleration. _____
True
______
11
)
When a car rounds a corner at constant speed, its acceleration is zero.
___
False (constant direction)
____
_
12
)
Even though a car is slowing
down, it
is still accelerating.
__
True
_________
13
)
Complete the following Units Table
Name of
Physical Quantity
Symbol
SI Unit
Time
t
s
Acceleration
a
m/s
2
Speed
v
m/s
Velocity
v
m/s
Displacement
Δd
m
Distance
d
m
Problems
:
Complete
using the required
GUESS method
!
14)
If the
average speed of a cheetah
is
21.7 m/s, how far can it run
in 3.0 seconds?
Diagram: (Given + Unknowns)
v = 21.7 m/s
Δd = ????? m
t = 3.0 s
Equation:
v
ave
=
Δd
t
Substitute:
21.7
=
Δd
Cross multiply
Δd = (21.7)(3.0)
3
Solve:
Δd
= 65.1 m
15
)
Starting from rest, a car undergoes a constant acceleration of 6.0 m/s
2
. How far will the car travel in the first
second of
travel?
Diagram: (Given + Unknowns)
a = 6 m/s
2
v
f
=
v
i
= 0 m/s
t = 1 s
Δd = ??? m
Equation
:
∆ d = (v
i
)t + (1/2) a (t)
2
Substitute:
∆ d = (0)(1) + (1/2)(6)(1)
2
Solve:
Δd = 3.0 m
16
)
How far does a car travel
with an acceleration of 4.0 m/s
2
take to go from 10 m/s to 30 m/s?
Diagram: (Given + Unknowns)
a = 4 m/s
2
v
f
= 30 m/s
v
i
= 10 m/s
t =
Δd = ??? m
Equation:
a =
(v
f
2
–
v
i
2
)
2Δd
=
S畢st楴u瑥:
=
4 =
(30
2
–
10
2
)
Switch the 4 and
Δd
Δd =
(30
2
–
10
2
)
2Δd
2(4)
Δd =
800
8
Solve:
Δd = 100 m
=
=
ㄷ
)=A瑯te=ropped=oml楦映w楴h
=
non楴楡l=veloc楴礮y⁔he=s瑯teas=a⁶er瑩calccelera瑩on映f.8/s
2
. After
it has fallen 128.6 m, what is the stone’s final velocity?
Diagram: (Given + Unknowns)
a = 9.8 m/s
2
v
f
= ??? m/s
v
i
= 0 m/s
t =
Δd = 128.6 m
Equation:
a =
(v
f
2
–
v
i
2
)
2Δd
=
Substitute:
9.8 =
(v
f
2
–
0
2
)
Cross Mult
2520.56
= v
f
2
2(128.6)
Take the square root : v
f
= 50.2 m/s
Solve:
v
f
= 50.2 m/s
18
)
In the story of the tortoise and
hare, a hare traveling 0.75 m/s accelerates uniformly for 3 second to pass
the tortoise. The hare travels 38.25 m during the 3 second interval that it was accelerating. What is the hare’s
speed at the end of the acceleration period?
Diagram: (Given +
Un
knowns)
a =
v
f
= ??? m/s
v
i
= 0.75 m/s
t = 3 s
Δd 38.25 m
Hint:
Find a first
then find v
f
Equation:
∆ d = (v
i
)t
+
(1/2) a (t)
2
a =
(v
f
–
v
i
)
t
Sub:
38.25
=
(0
.75)(3) +
(1/2)(a)(3)
2
38.25 = 2.25+
4.5a subtract 2.25
36
= 4.5a divide
8 m/s
2
= a
8 =
(v
f
–
0.75)
Cross Mult
3
24 = v
f
–
0.75
then add
.75
24.75 m/s = v
f
Solve:
v
f
= 24.75 m/s
19
)
What is the acceleration of a car that was traveling at 30 m/s and hit brakes to come to a stop in 1.7 s ?
Diagram: (Given + Unknowns)
a = ???
m/s
2
v
f
=0 m/s
v
i
= 30 m/s
t = 3 s
Δd =
Equation:
a =
(v
f
–
v
i
)
t
Substitute:
a =
(0
–
30)
1.7
Solve:
a =

17.6 m/s
2
20
)
From the position vs time graph
(left)
, draw the proper translation of a velocity vs time and acceleration vs
time g
raph
using the middle and right graphs
.
LABEL
SI
UNITS ON ALL GRAPHS ON THIS
AND THE FOLLOWING
PAGE
21
)
Describe the acceleration in the following situations:
a
.
Acceleration from 0 to 4 sec:
(negative acceleration)
b. Acceleration from 4 to 6 sec:
(zero acceleration)
c. Acceleration from 6 to 10 sec:
(positive acceleration)
0
2
4
6
8
10
0
0.5
1
1.5
2
Position
Time
Relationship between Position
and Time
2.5
2
1.5
1
0.5
0
0.5
1
1.5
2
2.5
0
1
2
3
4
5
Velocity
Time
Relationship of Velocity vs Time
2.5
2
1.5
1
0.5
0
0.5
1
1.5
2
2.5
0
1
2
3
4
5
Acceleration
Time
Relationship of Acceleration vs
Time
2
4
6
8
10
2
4
6
8
time
velocity
Use the
following Position vs
.
Time
graphs
to answer the
next six
questions.
The reference point is at 0 m.
M
ultiple graphs are possible answers to these questions.
Graph
choices can be used more than once.
22
)
Which
of the following graph(s) shows motion with
constant non

zero acceler
ation? ____
A and B
_
________
23
)
Which of the following graph(s)
shows motion towards the reference point? ___________
C
__________
24
)
Which of the following graph(s) shows motion with positive constant velocity? _________
D
__________
25
)
Which of the following
graph(s) shows
motion where the object is speeding up? _
_______
B
__________
26
)
Which of the following graph(s) shows motion with no acceleration? _______
C and D
____________
27
)
Which of the following graph(s) shows motion with a negative changing velocity? ____
none
__
____________
28) Draw a velocity vs t
ime and an acceleration vs time graph that
would show a cat moving with constant velocity
in the positive direction.
0
0.5
1
1.5
2
0
0.5
1
1.5
2
Position
Time
Graph A
0
0.5
1
1.5
2
0
0.5
1
1.5
2
Position
Time
Graph B
0
0.5
1
1.5
2
0
0.5
1
1.5
2
Position
Time
Graph C
0
0.5
1
1.5
2
0
0.5
1
1.5
2
Position
Time
Graph D
2.5
2
1.5
1
0.5
0
0.5
1
1.5
2
2.5
0
1
2
3
4
5
Velocity
Time
Relationship Velocity vs Time
2.5
2
1.5
1
0.5
0
0.5
1
1.5
2
2.5
0
1
2
3
4
5
Acceleration
Time
Relationship Acceleration vs Time
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