Download PreAP Physics Extra Practice Unit 1: Uniform Motion and Graphing

PreAP Physics Extra Practice
Unit 1: Uniform Motion and Graphing
1. Identify the following as scalar or vector quantities:
a. 55 mi/hr North
b. 28 m/s2
c. 3 km
d. 82 km west
e. 240 m/s
2. Two physics teachers challenge each other to a 100 m race across the football field. The
loser will grade the winner’s physics labs for one month. Mrs. Jensen runs the race in
10.4 seconds. Mr. Avis runs the first 25 m with an average speed of 10 m/s, the next 50
meters with an average speed of 9.5 m/s, and the last 25 m with an average speed of
11.1 m/s. Who gets stuck grading physics labs? [Mrs. Jensen by 0.39 sec]
3. A tortoise and a hare are in a road race to defend the honor of their breeds. The tortoise
crawls the entire 1000 m distance at a speed of 0.2 m/s while the hare runs the first 200
m at 2 m/s. The hare then stops to take a nap for 1.3 hours and awakens to finish the
last 800 m with an average speed of 3 m/s. Who wins the race and by how much time?
Draw a graph of position vs. time for the situation. [Tortoise by 46.67 s]
4. Hans stands at the rim of the Grand Canyon and yodels down to the bottom. He hears
his yodel echo back from the canyon floor 5.2 seconds later. Assume that the speed of
sound in air is 340 m/s. How deep is the canyon at this location? Draw a position vs.
time graph and a velocity vs. time graph of the motion. [884 m]
5. It is now 10:29 am, but when the bell rings at 10:30 am, Suzy will be late for French
class for the third time this week, which will cause her to lose final exemptions. She must
get from one side of the school to the other by hurrying down three different hallways.
She runs down the first hallway, a distance of 35 m, at a speed of 3.5 m/s. The second
hallway is filled with students and she covers its 48 m length at an average speed of 1.2
m/s. The third hallway is empty, Suzy sprints its 60 m length at a speed of 5 m/s. Does
Suzy make it to class on time or does she lose exemptions? Draw a position vs. time
graph of the situation. [2 seconds late]
(Assume all halls are parallel and she is running in the + direction)
6. A jumbo jet taxiing down the runway receives word that it must return to the gate to pick
up an important passenger who was late to his connecting flight. The jet is traveling at
45 m/s when the pilot receives the message. What is the acceleration of the plane if it
takes the pilot 5 seconds to bring the plane to a halt? [-9.00 m/s2]
7. Vivian is walking to the hairdresser’s at 1.3 m/s when she glances at her watch and
realizes that she is going to be late for her appointment. Vivian gradually quickens her
pace at a rate of 0.09 m/s2. What was Vivian’s speed after 10 s? Draw a position vs.
time graph and a velocity vs. time graph of the motion. [2.20 m/s]
8. Nathan accelerates his skateboard uniformly along a straight path to the east from rest
to 12.5 m/s in 2.5s.
a. What is Nathan’s acceleration? [5 m/s2]
b. What is Nathan’s displacement during this time interval? [15.63 m]
c. What is Nathan’s average velocity during this time interval? [6.25 m/s]
Page 58
PreAP Physics Extra Practice
9. Use the following velocity vs. time graph for a shuttle bus moving along a straight path to
answer the following questions:
a. Identify the time intervals during which the velocity
of the shuttle bus is constant
b. Identify the time intervals during which the
acceleration of the shuttle bus is constant.
c. Identify the times at which the velocity of the shuttle
bus is zero.
d. Identify the times at which the acceleration of the
shuttle bus is zero.
e. Explain what the shape of the graph reveals about
the acceleration in each time interval.
10. Answer the following questions about the car whose motion
is graphed in the following position vs. time graph:
a. When was the car 20 m west of the origin?
b. The car suddenly reversed direction. When and
where did that occur?
c. Where was the car at 50 s?
d. Describe the motion of the car.
11. Describe the motion of the object in the following graphs and then sketch the graph that
corresponds to it:
v
t
v
t
s
t
Page 59
PreAP Physics Extra Practice
s
t
12. Calculate the total displacement of the object whose motion is described in the velocitytime graph below: [32m]
13. Which point or points on the v-t graph (if any) show instants at which there was:
v
t
a. Uniform motion in the positive direction? _________
b. Uniform motion in the negative direction?
c.
Rest? _______
d. Positive acceleration with positive velocity? ________
e. Negative velocity with positive acceleration? _______
f.
Negative acceleration with positive velocity? ________
g. Negative velocity with negative acceleration? _________
h. Zero velocity and negative acceleration? _______
i.
Positive acceleration and zero velocity? ________
Page 60
PreAP Physics Extra Practice
Unit 3: Vectors and Projectiles
1. Add the following vectors:
a. John walks 14 m east and then walks 17 m west. What is his displacement? [-3
m]
b. 14 m east & 12 m north [18.44 m at 40.60o]
c. 13 m west & 8 m south [15.26 m at 211.61o]
d. 12 m at 230o and 14 m at 43o and 22 m at 174o [19.53 m at 172.17o]
2. Find the horizontal and vertical components of the following vectors:
a. 33 m/s at 47o [x = 22.51 m/s; y = 24.13 m/s]
b. 21 m at 317o [x = 15.36 m; y = -14.32 m]
3. Find the resultant of the following vectors using the parallelogram rule (“ruler slide”
method)
a. 4 cm at 120o & 3 cm at 200o
b. 6 cm at 318o & 5 cm at 75o
4. Calculate the magnitude and direction of the resultant of the vectors in #3.
a. [5.40 cm at 153.25 o]
b. [5.81 cm at 8.12 o]
5. What two things determine the motion of a projectile?
6. What is the name of the path of a projectile and what is its shape?
7. The ideal angle for the longest range is _________.
8. What component of motion determines the time of flight?
9. Name two ways to find the time of flight for a projectile shot from the ground that lands at
the same height as it was shot from.
10. Draw the trajectory for (a) an object shot at an angle from some distance above the
ground and (b) an object shot from the ground at some angle above the horizontal that
lands on the ground some horizontal distance away.
a. Label the points on the trajectory where the vertical component of the velocity is
zero.
b. Label the point on the trajectory where the vertical component of the velocity is a
maximum.
11. What is the acceleration in the horizontal direction for any projectile?
12. What is the vertical acceleration for any projectile? What causes this acceleration?
13. Explain how to find the net velocity of a projectile as it strikes the ground if you are given
the final vertical and horizontal velocities.
14. A rocket is launched with an initial velocity of 52 m/s at an angle of 32 o above the
horizontal.
a. How long is the rocket in the air? [5.62 s]
b. What is the maximum height of the rocket? [38.74 m]
c. How far away does the rocket land? [247.84 m]
15. A car drives horizontally off the top of a 55 m cliff and lands 105 m away from the base.
a. How long did it take for the car to crash? [3.35 s]
b. How fast was the car driving when it went over the edge? [31.34 m/s]
Page 61
PreAP Physics Extra Practice
16. A plane traveling 300 m/s horizontally drops a bomb which hits its target 12.0 s later.
How high was the plane flying? [705.6 m]
17. An arrow has a launching angle of 40o above the horizontal and an initial speed of 21
m/s.
a. What is the highest barrier the arrow can clear? [9.30 m]
b. How far away does the arrow land? [44.30 m]
c. If the angle is changed to 45 o and the initial speed remains the same, how much
farther does the arrow fly? [0.586 m farther]
18. A major league pitcher can throw a baseball 54 m/s. If a ball is thrown horizontally at this
speed, how much can it be expected to drop due to gravity by the time it reaches the
catcher who is 22 m away? [0.82 m]
19. A helicopter is traveling horizontally with a speed of 26 m/s at an altitude of 160 m, when
a passenger accidentally drops his sunglasses over the edge. What is the velocity of his
sunglasses as they smash into the ground below? [61.74 m/s at 294.91 o]
20. From the edge of a 60.0 m cliff, a small rocket is launched upward with an initial velocity
of 23.0 m/s at an angle of 50 o with respect to the horizontal. At what point above the
ground does the rocket strike the wall of a vertical cliff located 20.0 m away? [74.86 m]
21. A gull decides to hit you with a little surprise while you’re stretched out on your towel.
When the gull is 6 m above the ground and flying at 10 m/s at 40 he releases his
surprise.
a. How high above the ground does the little poop bomb travel? [8.11 m]
b. How long is it in flight? [12.66 s]
22. The fastest recorded pitch in Major League Baseball was thrown by Nolan Ryan in 1974.
When this pitch was thrown horizontally, the ball fell 0.809 m by the time it reached
home plate, 18.3 m away. How fast was Nolan Ryan’s pitch? [44.63 m/s]
23. A daredevil is shot out of a cannon at 55.0 o to the horizontal with an initial speed of 35.0
m/s. A net is positioned at a horizontal distance of 50.0 m from the cannon. At what
height above the cannon should the net be placed in order to catch the daredevil? [41.01
m]
24. During a thunderstorm, a tornado lifts a car to a height of 125 m above the ground.
Increasing in strength, the tornado flings the car horizontally with an initial speed of 90.0
m/s.
a. How far horizontally does the car travel before hitting the ground? [454.5 m]
b. What is the impact velocity of the car? [102.71 m/s @ 331.19o]
25. A boat is traveling at 4.5 m/s directly across a river while the river’s current is traveling at
2.3 m/s. What is the boat’s resultant velocity relative to the shore? [5.05 m/s @ 62.93 o]
26. Mr. Avis is running at 7.5 m/s when he passes Ms. Jensen running in the same direction
at 2.5 m/s.
a. What is his velocity relative to her?
b. If he is still running at 7.5 m/s when he passes a car traveling 15 m/s in the
opposite direction, what is the car’s velocity relative to him?
Page 62
PreAP Physics Extra Practice
Unit 4: Newton’s Laws
1. If a mass of 2 kg is accelerating across a frictionless surface to the right at a rate of 2
m/s2, what is the net force on the object? [4 N] What is the normal force on the mass?
[19.6 N]
2. If a 5 N force is accelerating a body at 5 m/s2 to the right across a frictionless surface,
what is the mass of the object? [1 kg] If it starts at 15 m/s, how far does it go in 10
seconds? [400 m]
3. Explain the difference between force and mass in terms of their effect on acceleration.
4. If you start with an acceleration of 10 m/s2, what would your new acceleration be if you
triple the mass and quadruple the force? [13.33 m/s2]
5. A 1500 kg car can accelerate uniformly at 4 m/s2. What will its acceleration be if it
accelerates while pulling another car of the same mass? Explain why. [2 m/s2]
6. A force of 750 N is applied to slide a mass of 110 kg to the right. The coefficient of
kinetic friction is 0.23. Find the force of friction, normal force, force of gravity, net force
and acceleration. [FFR = 247.94 N, FN = 1078 N, Fg = 1078 N, Fnet = 502.06, a = 4.564
m/s2]
7. A 2 kg ball is hanging from a rope and is accelerating upward at 1 m/s 2. What is the
tension in the rope? [21.6 N] What is the tension in the rope if the acceleration is down
at 2 m/s2? [15.6 N]
8. A Buick Skylark has a mass of 1500 kg and can accelerate to 1200 m/s in 8 seconds.
What is the net force acting on the car? [225000 N]
9. A 35 kg box is sliding on a rough table. If the net force is 45 N and the coefficient of
friction is 0.225, what is the applied force? [122.175]
10. An elevator accelerates up at 2.5 m/s/s. A man in this elevator weighs 700 N. What is
the mass of the man? [71.429 kg] What is the scale reading as he accelerates up?
[878.573 N]
11. What is the mass of a man who is in an elevator that is accelerating down at 4 m/s/s and
he is standing on a scale that reads 900 N. [155.17 kg]
12. A bullet is shot into a block of wood and penetrates a distance of 0.07 m into the wood
until the friction force stops it.
a. If the bullet was going 60 m/s, what was the deceleration? [- 25714 m/s2]
b. If the mass of the bullet was 0.03 kg, what was the stopping force? [-771.429 N]
13. Police find skid marks 60 m long on the highway showing where a car made an
emergency stop due to friction of the brakes. Assuming that the friction force was 10 N
and the car is 350 kg, how fast was the car going? [1.853 m/s]
14. Mr. Physics buys a 20 kg sheet of plywood at Home Depot. How much force is required
to pull the top sheet off the pile if the coefficient of friction is 0.23 and the board
accelerates at 2.2 m/s2? [89.08 N]
15. Jane is riding in an elevator while standing on a scale. She weighs 300 N.
a. What is Jane’s mass? [30.612 kg]
b. What does the scale read when the elevator is accelerating up at 1.5 m/s/s?
[345.918 N]
c. What does the scale read when the elevator is moving at a constant
velocity?[300 N]
Page 63
PreAP Physics Extra Practice
16. Identify which law goes with the following examples.
a. ______ A child coasting on ice has to use a tree to come to a stop.
b. ______ When stepping off of a boat the boat moves backwards
c. ______ A car with a large load drives more sluggishly.
d. ______ It takes a full elevator longer to reach the top than and empty elevator.
e. ______ The Paris gun (a big cannon used in WWI) moves backwards when
fired.
f. ______ All of the papers on the front seat fall off when the brakes are slammed
on.
16. A force of 750 N is applied to slide a mass of 110 kg to the right. The force of friction
that opposes this motion is 150 N. Find the weight of the mass, the normal force, and
the acceleration of the object. [Fg = 1078 N, FN = 1078 N, a = 5.455 m/s2]
17. A force of 300 N is sufficient to keep a 100 kg wooden crate moving at constant velocity
across a wooden floor. What is the coefficient of sliding friction? [0.306]
18. A 1000 kg truck going 75 km/hr slides 70 m to a stop. Find the coefficient of kinetic
friction. [0.316]
19. The coefficient of kinetic friction between a rubber tire and the road is 0.5. Find the
minimum time in which a 1500 kg car whose initial velocity is 26.8 m/s will stop. What
distance will the car cover in this time? [t = 5.469 sec, ∆s = 73.290 m]
20. Choose the best answer:
Kinetic friction:
a. increases as the normal force increases
b. is less than or equal to static friction
c. is the force to overcome when an object is moving at a constant velocity.
d. all of the above
21. According to Newton’s ____ Law, an object with no net force acting on it can move with
a constant velocity.
22. Newton’s _____ law states that the larger the force the larger the acceleration and the
larger the mass the smaller the acceleration.
23. Two teams in a tug of war exert the same amount of force on each other and the rope
does not move. Newton’s _____ law explains why the rope doesn’t move.
24. Choose the best answer:
Difficulty in pushing a large crate from rest involves
a. gravity
b. kinetic friction
c. static friction
d. balanced forces
25. At the surface of Mars, acceleration due to gravity is g = 3.7 m/s 2. A watermelon weighs
64 N on Earth.
a. What is its mass on Mars? [6.531 kg]
b. What is its weight on Mars? [24.165 N]
Page 64
PreAP Physics Extra Practice
Unit 5: Newton’s Laws Part 2
1. A boy exerts a 36 N force at 25o to the horizontal as he pulls a 52 N sled across a
cement sidewalk at constant speed. What is the coefficient of kinetic friction between the
sidewalk and the metal sled runners? [μk = 0.887]
2. A 52 N sled runs on packed snow. The coefficient of friction is 0.12. If a person sits on
the sled so the total weight of sled and person is 650 N, what force at 25o to the
horizontal is needed to pull the sled across the snow at constant speed? [81.504 N]
3. A sled of mass 50 kg is pushed at 15o to the horizontal. The static friction coefficient is
0.30 and the kinetic friction coefficient is 0.10.
a. What does the sled weigh? [490 N]
b. What is the magnitude of the force needed to start the sled moving? [165.17 N]
c. What is the magnitude of the force needed to keep the sled moving at constant
velocity? [52.13 N]
d. Once moving, what total force must be applied to the sled to accelerate it at 3 m/s?
[210.81 N]
4. Consider the following arrangement with m 1 = 10.0 kg, m2 = 15 kg and the coefficient of
kinetic friction is 0.30. Find the acceleration of the system and the tension in the cord.
[4.704 m/s2, 76.44 N]
a
M1
M2
5. Two blocks are connected by a cord on a horizontal surface. A force, F, pulls on the
blocks, as shown below. Find the acceleration and the tension in the connecting cord if
the coefficient of kinetic friction is 0.20. [5.183 m/s2, 19.286 N]
0.8 kg
2.7 kg
Fpull = 25 N
6. Find the tension in the cords and the acceleration of the system along the frictionless
surface. [5.13 m/s2, T1 = 136.17 N, T2 = 161.968 N]
a
5 kg
T1
T2
90 kg
45o
10 kg
60o
45o
Page 65
PreAP Physics Extra Practice
7. A 62 kg mass is sliding up a 15o incline and is opposed by a 92 N frictional force.
a. What is the acceleration of the object? [ - 4.020 m/s2]
b. What is the normal force? [586.897 N]
8. A box is sliding down a 22o incline with a surface having a coefficient of kinetic friction of
0.19. What is the box’s acceleration? [1.945 m/s2]
9. A 259 N box is pushed with an applied force at an angle of 45o with the horizontal. What
is the value of the applied force needed to get the box sliding if the μs = 0.49. [351.55 N]
10.
a
20 kg
10
kg
37o
Find the tension in the cord and the acceleration of the frictionless system. [104.65 N. 0.665
m/s2]
11. A 425 N block rests on a horizontal surface. The box is pulled with a force of 142 N at an
angle of 60o with the horizontal.
a. Determine the coefficient of static friction if the applied force is just enough to get the
box to move. [0.235]
b. Determine the coefficient of kinetic friction if the same applied force causes the box
to accelerate at 0.505 m/s2. [0.163]
12. A dockworker is sliding a crate of fish up a 10.0o ramp. The coefficient of kinetic friction
is 0.050 and he exerts a pulling force parallel to the incline of 80 N. What is the mass of
fish in the crate if it slides up the incline with constant speed? [36.65 kg]
13. A locomotive is pulling two freight cars with an acceleration of 0.520 m/s2. The mass of
Car 1 is 51,300 kg, while the mass of Car 2 is 18,400 kg. Find the tension in the rope
between the first car and the engine (T 1) and the tension in the rope between the two
cars (T2). [T1 = 36244 N, T2 = 9568 N]
Car 2
Car 1
T2
T1
Fengine
14. A 205 kg log is being pulled up a ramp by means of a rope that is parallel to the ramp.
The ramp is inclined at 30o with respect to the horizontal. The coefficient of kinetic
friction between the log and the ramp is 0.90 and the
log has an acceleration of 0.80 m/s2. Find the tension
in the rope. [2734.361 N]
15. Find T1 T2 and T3 in the diagram below. [T1 = 147 N,
T2 = 207.889 N, T3 = 147 N]
Page 66
PreAP Physics Extra Practice
16. Find the acceleration of the system and the tension in the cord. [33.688 N, 3.675 m/s 2]
17. Block 1 weighs 96 N. The coefficient of static friction between the block and the table is
0.50. Find the maximum weight for block 2 for which the system will remain in
equilibrium. [36.171 N]
18. Dr. Schmo, explorer extraordinaire, is hanging over a river of alligators as he waits for
his helicopter rescue to arrive.
a. If his weight is 450 N, find the tensions in each side of the rope. [T 1 = 678.2 N, T2 =
633.803 N]
b. If the max tension of the rope is 650 N, will he survive? Why? [no]
19. Find the acceleration of the system and the tension in the rope if the coefficient of kinetic
friction is 0.250. [3.286 m/s2]
Page 67
PreAP Physics Extra Practice
Unit 6: Circular Motion and Gravity (See Table of Information in the Appendix)
1.
When a car goes around a curve, what force keeps the car on the road?
2.
What is the direction of the centripetal acceleration of an object in uniform circular motion? Why?
3.
A ball is whirled around in a circle. What happens to the centripetal acceleration if the velocity is
doubled?
4.
If a string breaks that holds a whirling can in it circular path, what causes it to move in a straight
line path?
5.
What is the centripetal force that keeps a satellite in orbit above the earth?
6.
According to Newton’s law of universal gravitation, the force of gravitational attraction between any
two masses is directly related to the _______________ of the objects and inversely related to the
__________ of the distance between their centers.
7.
A 2400 kg car rounds a curve of radius 90.8 m with a speed of 12.50 m/s. If its wheels are on the
verge of slipping on the road, what is the force of friction? [4129.956 N]
8.
Determine the speed of channel 19’s communications satellite orbiting at a height of 5.96 x 10 5 m
above the earth’s surface. [7561.51 m/s]
9.
A model airplane is guided in a horizontal circular path by a cord of length 11 m. If it has a
constant speed of 28 m/s and a mass of 0.90 kg, what is the tension in the cord? [64.145 N]
10. What is the centripetal acceleration of an object moving in a horizontal circular path of 0.045 km
radius with a speed of 40 m/s? [35.556 m/s2]
11. The radius of the moon’s path about the earth is about 3.84 x 108 m. The moon’s period is 27.3
days. What is the centripetal acceleration of the moon? [0.0027 m/s 2]
12. A child whirls a stone of mass 6.7 kg in a vertical circle on the end of a string 0.8 m long. The
velocity of the stone is 14 m/s.
a. Calculate the tension in the string at the bottom of the circle. [1707.16 N]
b. What is the tension in the cord at the top of the circle? [1575.84 N]
13. An automobile travels around a circular track of radius 430 m at a speed of 22 m/s. What is the
coefficient of friction needed to keep this car on the track? [0.115]
14. The planet Neptune has two known moons – Triton and Nereid. Triton, which is larger than our
moon, orbits at a distance from Neptune’s center of 3.48 x 10 5 km in 5.9 days. What is Triton’s
velocity? [4289.369 m/s]
15. What is the weight, in N, of a 6 kg mass at the surface of the planet Persephone if the acceleration
due to gravity is 6.5 m/s2? [39 N]
16. A communications satellite of mass 600 kg is in circular orbit of radius 8.38 x 10 6 m above the
Earth’s surface. What is the gravitational force on the satellite? [1098.51 N]
17. The Enterprise, of mass 7.00 x 106 kg is in a 543 m radius orbit around a spaceport for repairs and
rest. If the spaceport has a mass of 2.8 x 109 kg, how fast is the ship moving in its orbit? [0.019
m/s]
18. Two balls have their center of mass 10.0 m apart. One weighs 39.2 N, the other weighs 39.2 N.
what is the gravitational force between them? [1.067 x 10 -11 N]
19. A 2 kg bucket of water is tied by a rope and whirled in a circle with a radius of 1.2 m. At the top of
the circular loop, the speed of the bucket is 3.8 m/s.
a. Determine the acceleration, the net force and the individual force values when the bucket is at
the top of the circular loop. [12.033m/s2, T = 4.467 N, Fnet = 24.067 N, Fg = 19.6 N]
b. Determine the acceleration, the net force and the individual force values when the bucket is at
the bottom of the circular loop, if it is traveling at 4.6 m/s. [17.633 m/s 2, T = 54.867 N, Fnet =
35.267 N, Fg = 19.6 N]
Page 68
PreAP Physics Extra Practice
Unit 7: Momentum and Impulse
1. In order to catch a ball, a baseball player moves his or her hand backward in the
direction of the ball's motion. Doing this reduces the force of impact on the player's hand
principally because __________.
A) the velocity of the hand is reduced.
B) the time of impact is decreased.
C) the momentum of impact is reduced.
D) the time of impact is increased.
E) none of the above
2. Two gliders having the same mass and speeds move toward each other on an air track
and stick together. After the collision the velocity of the gliders is __________.
A) twice the original velocity.
B) There is not enough information to say.
C) one half the original velocity.
D) zero.
E) the same as the original velocity.
3. A piece of putty moving with 1 unit of momentum strikes and sticks to a heavy bowling
ball that is initially at rest. After the putty sticks to the ball, both are set in motion with a
combined momentum that is __________.
A) Not enough information to say
B) more than 1 unit.
C) 1 unit.
D) less than 1 unit.
4. A 4-kg ball is thrown at 8 m/s. What is the ball's momentum? [32 kg m/s]
5. A 10-kg ball has a momentum of 55 kg m/s. What is the ball's velocity? [5.5 m/s]
6. A ball is moving at 8m/s and has momentum of 56kg m/s. What is the ball's mass? [7kg]
7. True/ False When two objects collide and completely bounce apart with no lasting
deformation or generation of heat, the collision is said to be elastic.
8. True/False When two objects collide and completely stick together, the collision is said
to be inelastic.
9. True/False Automobile dashboards that are padded lengthen the time of impact in case
of a collision.
10. A 5.0-kg blob of clay moving horizontally at 2.0 m/s has a head-on collision with a 6.0-kg
blob of clay that moves toward it at 1.0 m/s. What is the speed if the two blobs stuck
together immediately after the collision? [0.364 m/s]
11. A 0.215-kg hockey puck moving at 53 m/s is caught by a 70-kg goalie at rest. With what
velocity does the goalie slide on the ice after catching the puck? [0.162 m/s]
12. A 0.044 kg bullet strikes a 6.0-kg stationary wooden block and embeds itself in the
block. The block and bullet move together at 9.7 m/s. What was the original velocity of
the bullet? [1332.427 m/s]
13. A 48 g bullet moving at 500 m/s strikes a 3.2 kg wooden block. The bullet passes
through the block, leaving at 225 m/s. The block was at rest when it was hit. How fast is
it moving when the bullet leaves? [4.125 m/s]
14. A 0.75-kg ball traveling at 7.3 m/s rightward collides head-on with a 1.15-kg ball moving
in the opposite direction at a velocity of 13.0 m/s. The 0.75-kg ball moves away at 16
m/s leftward after the collision. Find the velocity of the second ball. [2.196 m/s]
15. A 3500-kg truck moving rightward with a speed of 7 km/hr collides head-on with a 1200kg car moving leftward with a speed of 11 km/hr. The two vehicles stick together and
move with the same velocity after the collision. Determine the post-collision velocity of
the car and truck. [0.668 m/s]
16. During a goal-line stand, a 80-kg fullback moving eastward with a speed of 8.6 m/s
collides head-on with a 110-kg lineman moving westward with a speed of 4.8 m/s. The
two players collide and stick together, moving at the same velocity after the collision.
Determine the post-collision velocity of the two players. [0.842 m/s]
Page 69