The electric motor of a model train accelerates the train from rest to 0.740 m/s in 30.0 ms. The total mass of the train is 560 g. Find the average power delivered to the train during its acceleration.

= 5.1 W

Explanation:

time (t) = 30 ms = 0.03 s

mass (m) = 560 g = 0.56 kg

initial velocity (U) = 0 m/s

final velocity (V) = 0.74 m/s

power = / frac{work done}{t} = / frac{f x d}{t} = f x v = m x a x v

m x a x v = m x / frac{V-U}{t} x / frac{V + U}{2}

m x / frac{V-U}{t} x / frac{V + U}{2} = 0.56 x / frac{0.74 - 0}{0.03} x / frac{0.74+0}{2}

= 5.1 W