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A train is traveling up a 3.9 degrees incline at a speed of 3.15m per s when the last car breaks free and begins to coast without friction. How long does it take for the last car to come to rest?
Wiki User
∙ 12y ago
the answer in the back of the book is 4.7 sec and i just can't figure it out
I don't get how the book got 4.7 seconds. I got .02 seconds because v=vo+at or velocity= initial velocity + acceleration *time. Thus, -.2/-9.81= .02 seconds.
Vinital=3.15m/s
A=gsin(3.9)
V=0
0=3.15m/s+9.81m/s^2*sin(3.9)t
So, -3.15m/s/(.667m/s^2)=t
t=-4.7
Wiki User
∙ 12y ago
Wiki User
∙ 15y agoThe car will never come to rest because you said that the car coasts without friction. Without friction, the car will never stop.
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Static friction does not apply when the block is already moving. Without friction, the force on the block parallel to the surface of the incline is Fg*sin(angle), so the acceleration without friction is 9.8* sin(30) = 9.8 * (1/2) = 4.9 Since it is accelerating at 3.2, friction is slowing down the block by (4.9-3.2 = 1.7). The coefficient of kinetic friction is (1.7/4.9) = 0.346939
When using the inclined plane what is the push or pull force?
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Without friction there would be?
NO friction
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You require friction in order to walk.
What would be like to climb a rope without friction?
Without friction - climbing a rope would be impossible !
What is examples of friction?
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Can a car move without motor running?
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friction is importent cause without it you can play baseball
What happens if there were no friction?
Without friction, objects would have no resistance, therefor loose no energy as a result. For example, without friction a ball could roll up and down a half-pipe continusily without loosing hight.
