A railroad diesel engine weighs four times as much as a freight car. If the diesel engine coasts at 13 km/h into a freight car that is at rest, how fast do the two coast after they couple?
2007-11-14 03:58:06 · 3 answers · asked by jrasta360 2 in Science & Mathematics ➔ Physics
If you consider both cars as part of the system before the collision then momentum of the two cars will be conserved.
mv1 = 13(4)
mv2 = V(5)
v2 = 13(4)/5 = 10.4 km/h
2007-11-14 04:06:52 · answer #1 · answered by Matt C 3 · 0⤊ 0⤋
Momentum is always conserved in collisions.
Let M bet the mass of the freight car.
Then the mass of the engine is 4M.
Initial momentum: (4M)(13 km/h) + 0
Final momentum (5M)(v)
Initial Momentum = Final Momentum
Set these expressions equal to each other, cancel the Ms, and solve for v.
2007-11-14 04:08:56 · answer #2 · answered by jgoulden 7 · 0⤊ 0⤋
forget with reference to the ramp and the slope. The kinetic capability on the backside is comparable to the aptitude capability on the desirable Ep at desirable = m*g*h Ek at backside = 0.5*m*v² Therfore, m*g*h = 0.5*m*v² Cancel out the hassle-unfastened m oneach element, and simplify V² = g*h/0.5 V² = 9.8* 124 *2 V² = 2430.4 V = 40 9.3m/s Her speed os 40 9.3 m/s (which i think of is an extremely extreme speed for a beginner skier)
2016-09-29 05:41:56 · answer #3 · answered by doble 4 · 0⤊ 0⤋