##### Page 1
I.
Two gliders, A and B, collide on a level, frictionless track, as shown below.
The mass of glider A is less than that of glider B (
i.e., m
A
<m
B
).
The ﬁnal speed of
glider A is greater than that of glider B (
i.e.,
v
Af
>
v
Bf
).
Is the magnitude of the ﬁnal momentum of glider A, |p
Af
|,
greater than, less than,
or
equal to
that of glider B, |p
Bf
|?
Draw a
momentum vector diagram
to support your
The change in momentum vectors for each block are equal in magnitude, but opposite
in directions.
Sketching this vector for block A allows us to sketch it for block B as
shown.
It is easy to see from the diagram that the ﬁnal momentum of B must be
larger than that of A if the change in momentum vectors are to be equal in magnitude.
II.
Two gliders, C and D, collide on a level, frictionless track, as shown below.
v
B
i
= 0
After collision
A
B
v
A
f
v
B
f
Before collision
A
B
v
A
i
initial momentum
ﬁnal momentum
change in momentum
Block A
Block B
Written homework 9
Name:_________________
Physics 101 - Andrew Crouse - Ithaca College
Fall
Tutorials in Introductory Physics,
McDermott, Shaffer, & P.E.G., U. Wash.
https://www.coursehero.com/file/9170223/HW9-SOL/
This study resource was
shared via CourseHero.com

##### Page 2
The mass of glider C is less than that of glider D (
i.e., m
C
<m
D
).
The initial speed of
glider C is greater than that of glider D (
i.e.,
v
Ci
>
v
Di
).
After the collision, Gliders C
and D move in opposite directions with the same ﬁnal speed,
v
f
.
Is the magnitude of the initial momentum of glider C, |p
Ci
|,
greater than, less than,
or
equal to
that of glider D, |p
Di
|?
Draw a
momentum vector diagram
to support your
The change in momentum vectors for each block are equal in magnitude, but opposite
in directions.
Sketching this vector for block C allows us to sketch it for block D as
shown.
The two blocks have the same ﬁnal velocity, but D has a larger mass.
Thus, D
has the larger ﬁnal momentum.
If the change in momentum vectors are to be equal in
magnitude the initial momentum of block D must be smaller than that of block C as
shown in the diagram.
v
D
i
After collision
C
D
v
C
f
v
D
f
Before collision
C
D
v
C
i
initial momentum
ﬁnal momentum
change in momentum
Block C
Block D
Written homework
9
Physics 101 - Andrew Crouse - Ithaca College
Fall