anyone have answers to these worksheets? links are down?

Question

http://www.kasd.org/~ddrummer/GP_Momentum_WS5_1.pdf#search='dummies%20worksheet'


http://www.kasd.org/~ddrummer/GP_Momentum_WS5_2.pdf#search='dummies%20worksheet'

Answer 1

These are too easy to answer. They're all conservation of momentum problems. Just remember that the total momentum of the system (the 2 vehicles) stays constant -- the same before and after the collision, whether they stay stuck together or not. Momentum is mass times velocity. When 2 vehicles are moving in opposite directions, their velocities must be given opposite signs. Thus when 2 vehicles collide and continue separately you have
m1*v1 + m2*v2 = m1*v1' + m2*v2'
(the ' symbol means post-collision)
When 2 vehicles collide and stay together you have
m1*v1 + m2*v2 = (m1+ m2) * v'
(v' is the post-collision velocity of the 2 vehicles)
So, just to solve one of the problems (#5), m1=2500, v1=20, m2=1000, v2=0, and they stick together. So m1*v1 + m2*v2 = 2500*20 + 1000*0 = 50000. Solving for post-collision velocity, v'=50000/(m1 + m2) = 50000/3500 = 14.29.