Name
Period
Date
Momentum: Worksheet 3
Inelastic Collisions
1. A 6.0 kg box sled is coasting across the ice at a speed of 9.0 m
when a 12 kg
s
package is dropped into it from above. What is the new speed of the sled?


v 2i
2. A block of mass m1  2.0 kg slides along a
v1i
frictionless table with a speed of 10. m .
k
s
m2
m1
Directly in front of it, and moving in the same
direction, is a block of mass m2  5.0 kg
moving at 3.0 m . A massless spring with spring constant k  1120 N is attached
s
m
to the near side of m2 as shown in the diagram.
a. At the moment of maximum
b. When the blocks collide, what is the
compression of the spring, the two
maximum compression of the spring?
blocks move as one. Find this
velocity by noting that the collision
is completely inelastic to this point.
Momentum: Worksheet 3 Inelastic Collisions
page 2
3. Two vehicles A and B are traveling West and South, respectively, toward the same
intersection where they collide and lock together. Before the collision, A (total
weight 2700 lb ) is moving with a speed of 40. mi and B (total weight 3600 lb ) has a
h
mi
speed of 60.
. Find the magnitude and direction of the velocity of the
h
(interlocked) vehicles immediately after the collision.
r
P
r
vo
2m
m
4. (1991 AP C) A small block of mass 2m initially rests on a track at the bottom of the
circular, vertical loop-the-loop shown above, which has radius r . The surface
contact between the block and the loop is frictionless. A bullet of mass m strikes the
block horizontally with initial speed vo and remains embedded in the block as the
block and bullet circle the loop. Determine each of the following in terms of m , vo ,
r , and g .
a. The speed of the block and the bullet immediately after impact.
Momentum: Worksheet 3 Inelastic Collisions
page 3
b. The kinetic energy of the block and bullet when they reach point P on the loop.
c. The minimum speed the block and bullet would need at the top of the loop to just
execute a complete circuit of the loop. Draw a force diagram of the block and
bullet at the top of the loop at this minimum speed.
d. The minimum initial speed vmin of the bullet if the block and bullet are to
successfully execute a complete circuit of the loop.
Momentum: Worksheet 3 Inelastic Collisions
page 4
5. (2006 AP B) A small block of mass M is released from rest at the top of the curved
frictionless ramp shown above. The block slides down the ramp and is moving with
a speed 3.5vo when it collides with a larger block of mass 1.5M at rest at the bottom
of the incline. The larger block moves to the right at a speed 2vo immediately after
the collision. Express your answers to the following questions in terms of the given
quantities and fundamental constants.
a. Determine the height h of the ramp
b. Determine the velocity (magnitude and
from which the small block was
direction) of the small block after the
released.
collision.
c. The larger block slides a distance D before
coming to rest. Determine the value of the
coefficient of kinetic friction  k between
the larger block and the surface on which it
slides.
d. Indicate whether the collision
between the two blocks is
elastic or inelastic. Justify your
answer.