Download Year 13 Momentum - Rogue Physicist

Year 13 Momentum
1) A spherical mass of 1.5kg travelling at a velocity of 2.5m/s collides with another spherical mass of 0.75kg,
which is initially at rest. The collision is inelastic such that they join and move away with a common velocity.
a) What is the initial momentum of each mass?
b) By applying the principal of conservation of momentum, find the velocity with which the masses move
away.
c) Show that the momentum before and after is equal both in magnitude and direction
d) Find the total kinetic energy of the system before and after the collision. comment on your answer.
2) Two ice skaters, initially at rest, push away from each other. The ice skaters have masses of 75kg and 65kg
respectively. The lighter skater moves away with a velocity of 1.5m/s to the left.
a) Find the velocity of the heavier skater.
b) Calculate the ratio velocity of skater 1:velocity of skater 2.
c) Calculate the ratio mass of skater 1:mass of skater 2. Is there a connection between the ratio of the masses
and the ratio of the velocities? (hint: try taking the reciprocal!)
3) Trolley A has a mass of 0.2kg and is travelling with velocity 0.1m/s when it is struck elastically from behind
by another trolley of mass 0.5kg travelling in the same direction. the velocity of trolley a increases to
0.715m/s, while trolley B slows down to a velocity of 0.315m/s.
a) what was the initial velocity of trolley B?
b) what was the relative velocity of the two trolleys before the collision?
c) what is the relative velocity of the trolleys after the collision?
d) has the total kinetic energy of the system been conserved?
e) find the ratio of the changes of velocity for the trolleys. What do you notice?
Year 13 Momentum
1) A spherical mass of 1.5kg travelling at a velocity of 2.5m/s collides with another spherical mass of 0.75kg,
which is initially at rest. The collision is inelastic such that they join and move away with a common velocity.
a) What is the initial momentum of each mass?
b) By applying the principal of conservation of momentum, find the velocity with which the masses move
away.
c) Show that the momentum before and after is equal both in magnitude and direction
d) Find the total kinetic energy of the system before and after the collision. comment on your answer.
2) Two ice skaters, initially at rest, push away from each other. The ice skaters have masses of 75kg and 65kg
respectively. The lighter skater moves away with a velocity of 1.5m/s to the left.
a) Find the velocity of the heavier skater.
b) Calculate the ratio velocity of skater 1:velocity of skater 2.
c) Calculate the ratio mass of skater 1:mass of skater 2. Is there a connection between the ratio of the masses
and the ratio of the velocities? (hint: try taking the reciprocal!)
3) Trolley A has a mass of 0.2kg and is travelling with velocity 0.1m/s when it is struck elastically from behind
by another trolley of mass 0.5kg travelling in the same direction. the velocity of trolley a increases to
0.715m/s, while trolley B slows down to a velocity of 0.315m/s.
a) what was the initial velocity of trolley B?
b) what was the relative velocity of the two trolleys before the collision?
c) what is the relative velocity of the trolleys after the collision?
d) has the total kinetic energy of the system been conserved?
e) find the ratio of the changes of velocity for the trolleys. What do you notice?