Conservation of Linear Momentum

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Conservation of Linear Momentum
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• CONSERVATION OF MOMENTUM
• Collisions
• momentum is always conserved in collisions
• momentum before momentum after

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• Example
• A 900 kg car is moving at 20.0 m/s when it
  collides with a 50.0 kg bale of hay at rest on
  the road. If the two objects remain together,
  determine their speed after the collision.

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2. A 5.30 kg wagon is moving at 2.00 m/s to the
right. A 0.180 kg blob of putty moving at 32.0
m/s also to the right strikes the wagon and
sticks to it. With what speed will the wagon and
the putty move after the collision?

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Explosions

• Remember if the momentum before the explosion
  is zero, then the momentum after the explosion is
  zero.

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• When a gun fires, the bullet goes one way, the
  gun goes in the opposite way (recoil). The
  momentum adds up to zero.

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• Example
• A 600 kg cannon fires a 35.0 kg person
  horizontally at 250 m/s, left. Determine the
  recoil velocity of the cannon.

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Assignment
p. 51 56 ALL