Consider a system consisting of both objects A and B. What is the
total initial momentum of this system, just before the
collision?
_{sys,i} =
kg
· m/s
The forces that A and B exert on each other are very large but last
for a very short time. If we choose a time interval from just
before to just after the collision, what is the approximate value
of the impulse applied to the twoobject system due to forces
exerted on the system by objects outside the system?
_{net}Δt
=
N
· s
Therefore, what does the momentum principle predict that the total
final momentum of the system will be, just after the
collision?
_{sys,f} =
kg
· m/s
Just after the collision, object A is observed to have momentum
_{A,f} = < 17, 4, 0 > kg
· m/s. What is the momentum of object B just after the
collision?
_{B,f} =
kg
· m/s
Before the collision, what was the magnitude of the momentum of
object A?

_{A,i} = kg
· m/s
Before the collision, what was the kinetic energy of object A?
Remember that you can calculate kinetic energy not only from
K = (1/2)
m
^{2} but more directly from
K = (1/2)
^{2}/
m.
K_{A,i} = J
Before the collision, what was the magnitude of the momentum of
object B?

_{B,i} = kg
· m/s
Before the collision, what was the kinetic energy of object
B?
K_{B,i} = J
After the collision, what was the magnitude of the momentum of
object A?

_{A,f} = kg
· m/s
After the collision, what was the kinetic energy of object A?
K_{A,f} = J
After the collision, what was the magnitude of the momentum of
object B?

_{B,f} = kg
· m/s
After the collision, what was the kinetic energy of object B?
K_{B,f} = J
Before the collision, what was the total kinetic energy of the
system?
K_{sys,i} =
K_{A,i} +
K_{B,i} = J
After the collision, what was the total kinetic energy of the
system?
K_{sys,f} =
K_{A,f} +
K_{B,f} = J What kind of collision was this?
(Remember that an "elastic" collision is one where the final value
of the total kinetic energy is equal to the initial value of the
total kinetic energy.)
not enough
information to decideelastic inelastic
Assume that all of the energy is either kinetic energy or thermal
energy. Calculate the increase of thermal energy of the two
objects.
ΔE_{A,thermal}
+
ΔE_{B,thermal}
= J
In the preceding analysis, what assumption did you make about
Q (energy flow from surroundings into the system due to a
temperature difference)?