If no braking occurs, a total of how much power would be required to keep the railcar moving at 40 m/s

40 kW

Explanation:

A railcar has a continuous 1000 N decelerating force any time it is in motion. If no braking occurs, how much power would be required to keep the railcar moving at 40 m/s

Solution:

Power in Physics is the rate of doing work and the work can be mechanical, electrical, etc. The S.I unit of power is the watts (W).

The power required to keep the car moving must match the work done by the friction force (decelerating force) that tends to slow down the railcar.

Work done = Force * displacement

Power = Work done / time = (Force * displacement) / time

Power = Force * (displacement / time)

Power = force * velocity = 1000 N * 40 m/s = 40000 W

Power = 40 kW

this is poiselle's equation from fluid mechanic in physics. mech eng