Period ____
Name __________________________
APP1 2020 Momentum and Collisions Worksheet 5.2
____
1. Two identical objects of mass M move with equal speeds v. The direction of their velocities is
illustrated above. The magnitude of the linear momentum of the system is _____.
a. 2Mv
b. Mv
c. 4Mv
d.
____
2. Two objects, one of mass M, and the other of 5M rest on a horizontal frictionless table with a
compressed spring of negligible mass between them. The spring is released and each object gains
kinetic energy. The object of mass M gains
a. 1/6 of the energy.
b. 1/5 of the energy.
c. 4/5 of the energy.
d. 5/6 of the energy.
1
____
3. Two objects of mass, m1 and m2, are moving with velocities
and
when they collide.
Immediately after the collision, the final velocities are
and
. Which of the following equations
best represents the relationship between either the horizontal or vertical components of the initial and
final momenta of the system?
a. m1v1x + m2v2x = m1v’1x + m2v’2x
b. m1v1y + m2v2y = m1v’1y + m2v’2y
c. m1v1x + m2v2x = m1v’1y + m2v’2y
d. (A) and (B)
____
4. A puck of mass m1 and initial velocity v1 collides elastically with a second puck of mass m2, which is
initially at rest. After the collision, m1 moves with velocity v1 at an angle (below the x axis) and m2
moves with velocity v2’ at an angle (above the x axis). Which of the following statements is true?
a. Momentum is conserved in the x direction.
b. Momentum is conserved in the y direction.
c. The kinetic energies are conserved.
d. All of the above statements are true.
____
5. A toy car of mass 2.0 kg moving to the right with a speed of 8.0 m/s collides completely inelastically
with another toy car of mass 3.0 kg that is moving to the left with a speed of 2.0 m/s. Immediately
after the collision the velocity of the system is __________.
a. 4.4 m/s to the right
b. 2.0 m/s to the right
c. 0 m/s
d. –2.0 m/s to the right
2
____
6. A railway car having a total mass of 5.8  105 kg, moving with a speed of 9.1 km/h, strikes another
car that has a mass of 8.7  105 kg and is initially at rest. The speed of the coupled cars after the
collision is _____.
a. 9.1 km/h
b. 7.2 km/h
c. 3.6 km/h
d. 1.8 km/h
____
7. A bullet of mass m and velocity
strikes and becomes imbedded in a wooden block of mass M,
which is initially at rest on a frictionless surface. The ratio of the velocity of the system after
collision to the initial velocity of the bullet is _____.
a.
b.
c.
d.
____
8. An 1810-kg truck traveling eastward at 64.4 km/h collides at an intersection with a 905-kg
automobile traveling northward at 96.5 km/h. The vehicles lock together and immediately after the
collision are headed in which direction?
a. 30o N of E
b. 37o N of E
c. 45o N of E
d. 53o N of E
3
____
9. A projectile with a mass 6M is launched at a speed of 400 m/s at an angle of 60o above the
horizontal. At the highest point of its trajectory, the projectile is broken into two equal pieces by an
internal explosion. Just after the explosion, one of the two pieces is known to be traveling vertically
downward at a speed of 300 m/s. The magnitude of the velocity of the other half of the projectile is
_____.
a. 500 m/s
b. 1.50 km/s
c. 400 m/s
d. 710 m/s
____ 10. A 7000-kg coal car of a train coasts at 7.0 m/s on a frictionless track when a 3000-kg load of coal is
dropped vertically onto the car. The coal car's speed after the coal is added is _____.
a. 2.1 m/s
b. 3.0 m/s
c. 4.9 m/s
d. 7.0 m/s
____ 11. A bullet (mass = m) is fired at speed v into a block of mass M (with M > m) which is hanging
vertically from a light string of length L. The bullet is embedded in the block. If the recoiling
block-bullet system reaches a height of 2/3L, then the initial speed of the bullet is most nearly
__________.
a. M  (1gL/3)1/2/m
b. M  (2gL/3)1/2/m
c. M  (3gL/4)1/2/m
d. M  (4gL/3)1/2/m
4
____ 12. A bullet of mass m is fired into a block of mass M attached to an uncompressed spring of spring
constant k, fixed at its other end. The speed of the bullet, v, can be found by measuring the maximum
distance, d, of compression of the spring. In this situation the initial speed of the bullet is given by
__________.
a.
b.
c.
d.
____ 13. An object of mass m1 = 2.5 kg is connected to another object of mass m2 = 4.0 kg by a compressed
spring. Both objects are at rest on a frictionless surface. When the spring is released, the objects are
pushed apart and a total energy of 16.8 J is given to the two objects. The speed of object m1 is
_____.
a. 3.2 m/s
b. 2.9 m/s
c. 1.8 m/s
d. 8.3 m/s
5
____ 14. A particle of mass m moving at 5.0 m/s in the positive x direction makes a glancing elastic collision
with a particle of mass 2m that is at rest before the collision. After the collision, m moves off at an
angle of 45o to the x axis and 2m moves off at 60o to the x axis. The speed of m after the collision is
_____.
a. 4.5 m/s
b. 2.5 m/s
c. 3.3 m/s
d. 1.8 m/s
____ 15. You shoot an arrow with a mass of 0.54 kg at 45o above the horizontal. The bow exerts a force of
125 N for 0.65 s. With no air resistance, the maximum height above the launch point the arrow
reaches is _____.
a. 1.2 km
b. 5.4 m
c. 0.57 km
d. 0.29 km
6