Conservation of momentum in one dimension

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Intros
Lessons
  1. Introduction to conservation of momentum in one dimension:
  2. Meaning of conservation of momentum
  3. Deriving conservation of momentum from Newton's third law
  4. Meaning of closed/open systems and identifying conservation of momentum problems
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Examples
Lessons
  1. pi=pf:\bold{\sum\vec{p}_i = \sum\vec{p}_f}: Objects that bounce apart after collision
    1. A 0.200 kg billiard ball travelling 7.00 m/s to the right collides with a stationary 0.0450 kg golf ball. The velocity of the billiard ball after collision is 4.43 m/s [right]. What is the velocity of the golf ball after collision?
    2. A 2.20 kg ball rolling 1.50 m/s [E] collides head-on with a ball rolling 2.40 m/s [W]. The 2.20 kg ball rolls away at 1.00 m/s [W] after the collision, and the second ball rolls 1.80 m/s [E]. What is the mass of the second ball?
    3. 4500 kg train car A travels at 6 m/s [E]. It collides with 3750 kg train car B which is travelling 3.2 m/s [E] on the same track. After the collision, train car A travels at 3.5 m/s [E]. Find the final velocity of train car B.
    4. A rifle points [E] at a 3.40 kg wood block. It fires a 22.0 g bullet travelling at 460.0 m/s, which passes through the block and continues at 299 m/s. Find the velocity of the wood block when the bullet leaves.
  2. pi=pf:\bold{\sum\vec{p}_i = \sum\vec{p}_f}: Objects that stick together after collision
    1. A rifle points [E] at a 3.40 kg wood block. It fires a 22.0 g bullet travelling at 460.0 m/s, which embeds in the block. Find the velocity of the bullet and the wood block after embedding.
    2. An 80.0 kg hockey goalie is gliding 0.230 m/s [W] when he catches an incoming 162 g puck travelling [W]. If the goalie then travels at 0.300 m/s [W], what is the velocity of the puck before he catches it?
    3. A 2575 kg truck travelling at 15.0 m/s right collides with a 1895 kg car reversing at 1.00 m/s to the left. The vehicles stick together after the collision.
      1. What is the velocity of the vehicles after the collision?
      2. If the crashed cars skid for 4.30 s after crashing, what is the average force of friction from the road acting on them?
  3. pi=pf:\bold{\sum\vec{p}_i = \sum\vec{p}_f}: Objects that explode apart
    1. A 68 000 kg rocket initially at rest in space fires a thruster which expels 43 kg of gas at 730 m/s [left]. Find the final velocity of the rocket.
    2. Two paddlers dock their canoe. The canoe is stationary when 72 kg paddler A steps out at 2.4 m/s forwards. This causes the canoe and 59 kg paddler B to move at a speed of 1.8 m/s. Find the direction that paddler B is moving in after paddler A steps out, and the mass of the canoe.
    3. A 3400 kg rail car carries a 200 kg cannon and a 15 kg cannonball along a level rail at 9.5 m/s [E]. The cannon fires the cannonball at 478 m/s [E]. Find the velocity of the rail car and cannon after firing.