frieght car that is initially at rest, how fast do the 2 coast after they couple together?
What is the answer and how did u figure out the answer?????
2006-09-16 13:04:51 · 3 answers · asked by wildbutterflychick 2 in Science & Mathematics ➔ Physics
Assuming no bounce (i.e., a non elastic collision so that the car and the engine travel at the same speed after the collision), the answer is 4km/h. The law of conservation of momentum states that the momentum before the collision is the same as the momentum after. If the car weighs W, then the engine weighs 4W. Momentum before the collision is 20Wkm/h (4W times 5km/h). The momentum after is the same, so divide the momentum by the combined weight of 5W and get 20Wkm/h : 5W = 4km/h.
2006-09-16 13:20:07 · answer #1 · answered by WoodyBretton 3 · 0⤊ 1⤋
Its one km/h after the coupling.
Let m= mass of engine then,
mass of freight car=4m
mass of the system of the coupled pieces is 4m+m=5m
momentum of engine at 5km/h=5units
momentum=mass*velocity
since the mass of the engine went up 5 times, the velocity must go down by 5 times.
2006-09-16 20:13:16 · answer #2 · answered by Ren Hoek 5 · 0⤊ 0⤋
It depends on the slope involved and the acceleration/deceleration of the engine.
2006-09-16 20:08:11 · answer #3 · answered by Scott K 7 · 0⤊ 1⤋