1. Given:
M1 = 80kg, V1 = 6.0m/s.
M2 = 100kg, V2 = -3.0m/s.
V3 = Velocity of M1 and M2 after colliding.
Momentum before = Momentum after.
M1*V1 + M2*V2 = M1*V3 + M2*V3.
80*6 + 100*(-3) = 80V3 + 100V3,
480 - 300 = 180V3,
V3 = 1m/s in the direction of M1 before colliding.
2.
1. An 80kg football player is running at the speed of 6.0m/s. A 100kg player is running towards the other player with a speed of 3.0m/s. At what speed are they travelling when they collide? Give the direction.
2. A reckless driver is driving __m/s and hits the break __m before the red light. He has a deceleration of -16m/s.
a) When does he come to a complete stop in the middle of the intersection?
b) When did he need to brake to make it before the intersection?
3. A driver is driving off a cliff with a speed of 2.0m/s.
a) How far down does he fall? (I think)
b) immediately after driving off the cliff, a rock falls into the water. At what speed does the rock hit the water?
1 answer