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 position
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 False:
5) The rate at which distance is covered is called speed.___True________
6) Average speed is defined as the time it takes for a trip divided by the distance traveled. _____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/s2________
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
Time
Acceleration
Speed
Velocity
Displacement
Distance
Symbol
t
a
v
v
Δd
d
SI Unit
s
m/s2
m/s
m/s
m
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)
Equation:
vave = Δd
v = 21.7 m/s
Δd = ????? m
t = 3.0 s
t
Substitute:
21.7 = Δd
3
Cross multiply
Δd = (21.7)(3.0)
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)
Equation: ∆ d =
(vi)t + (1/2) a (t)2
a = 6 m/s2
vf =
vi = 0 m/s
t = 1 s
Δd = ??? m
Substitute:
∆ d =
+ (1/2)(6)(1)2
(0)(1)
Solve:
Δd = 3.0 m
16) How far does a car travel with an acceleration of 4.0 m/s2 take to go from 10 m/s to 30 m/s?
Diagram: (Given + Unknowns)
Equation:
a = (vf2 – vi2)
a = 4 m/s2
vf = 30 m/s
vi = 10 m/s
t =
Δd = ??? m
2Δd
Substitute:
4 = (302 – 102)
2Δd
Δd = (302 – 102)
2(4)
Switch the 4 and Δd
Δd = 800
8
Solve:
Δd = 100 m
17) A stone is dropped from a cliff with no initial velocity. The stone has a vertical acceleration of 9.8 m/s 2. After
it has fallen 128.6 m, what is the stone’s final velocity?
Diagram: (Given + Unknowns)
Equation: a = (vf2 – vi2)
a = 9.8 m/s2
vf = ??? m/s
vi = 0 m/s
t =
Δd = 128.6 m
2Δd
Substitute:
9.8 = (vf2 – 02)
2(128.6)
Cross Mult
2520.56 = vf2
Take the square root :
vf = 50.2 m/s
Solve: vf = 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 +
Equation: ∆ d = (vi)t +(1/2) a (t)2
a = (vf – vi)
Unknowns)
a =
vf = ??? m/s
vi = 0.75 m/s
t = 3 s
Δd 38.25 m
Hint: Find a first
then find vf
t
Sub: 38.25=(0.75)(3) + (1/2)(a)(3)
2
8 = (vf – 0.75)
3
Cross Mult
38.25 = 2.25+4.5a subtract 2.25
24 = vf – 0.75
36 = 4.5a
2
then add .75
divide
24.75 m/s = vf
8 m/s = a
Solve:
vf = 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 ?
Equation: a = (vf – vi)
Diagram: (Given + Unknowns)
t
a = ??? m/s2
vf =0 m/s
vi = 30 m/s
t = 3 s
Δd =
Substitute:
a = (0 – 30)
1.7
Solve:
a = -17.6 m/s2
20) From the position vs time graph (left), draw the proper translation of a velocity vs time and acceleration vs
time graph using the middle and right graphs.
Relationship of Velocity vs Time
10
Velocity
Position
8
6
4
2
0
0
0.5
1
1.5
2
Time
2.5
2
1.5
1
0.5
0
-0.5 0
-1
-1.5
-2
-2.5
1
2
3
4
Relationship of Acceleration vs
Time
5
Time
Acceleration
Relationship between Position
and Time
2.5
2
1.5
1
0.5
0
-0.5 0
-1
-1.5
-2
-2.5
1
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:
velocity
(negative acceleration)
8
b. Acceleration from 4 to 6 sec:
6
(zero acceleration)
4
2
time
2
4
6
8
10
c. Acceleration from 6 to 10 sec:
(positive acceleration)
2
3
Time
4
5
Use the following Position vs. Time graphs to answer the next six questions. The reference point is at 0 m.
Multiple graphs are possible answers to these questions. Graph choices can be used more than once.
Graph B
2
2
1.5
1.5
Position
Position
Graph A
1
0.5
0.5
0
0
0
0.5
1
1.5
0
2
0.5
Time
Graph C
Graph D
2
2
1.5
1.5
1
0.5
1.5
2
1.5
2
1
0.5
0
0
0
0.5
1
1.5
2
0
0.5
Time
22)
23)
24)
25)
26)
27)
1
Time
Position
Position
1
Which
Which
Which
Which
Which
Which
1
Time
of the following graph(s) shows motion with constant non-zero acceleration? ____A and B_________
of the following graph(s) shows motion towards the reference point? ___________C__________
of the following graph(s) shows motion with positive constant velocity? _________D__________
of the following graph(s) shows motion where the object is speeding up? ________B__________
of the following graph(s) shows motion with no acceleration? _______C and D____________
of the following graph(s) shows motion with a negative changing velocity? ____none______________
28) Draw a velocity vs time and an acceleration vs time graph that would show a cat moving with constant velocity
in the positive direction.
Relationship Acceleration vs Time
2.5
2
1.5
1
0.5
0
-0.5 0
-1
-1.5
-2
-2.5
1
2
3
Time
4
5
Acceleration
Velocity
Relationship Velocity vs Time
2.5
2
1.5
1
0.5
0
-0.5 0
-1
-1.5
-2
-2.5
1
2
3
Time
4
5