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A 15,000lb freight car is pulled along a horizontal track.
Ifthe car starts from rest and attains a velocity of 40ft/s
aftertraveling a distance of 300ft.
determine the total work done on the car by the towing forcein
this distance if the rolling frictional force between the carand
the track is 80lb.

Respuesta :

klefenz

Answer:

12024000 lb*ft

Explanation:

The total work will be the sum of the energy consumed by friction plus the kinetic energy the car attained.

L = Ek + Lf

Lf = Ff * d

Ek = 1/2 * m * v^2

Therefore:

L = Ff * d + 1/2 * m * v^2

L = 80 * 300 + 1/2 * 15000 * 40^2 = 12024000 lb*ft

THe total work done on the car is of 12024000 lb*ft

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