JAMB - Physics (2022 - No. 35)
A train of mass 1600 kg attains a speed of 25 ms\(^{-1}\) in 20 seconds. The power developed in the engine is?
2.5 KW
80 KW
25 KW
50 KW
Explanation
where force = f, mass = m, acceleration = a, velocity = v, time = t
Force = m * a → m * \(\frac{Δv}{t}\)
Power = f * v
P = m * \(\frac{v}{t}\) * v = m * \(\frac{v^2}{t}\)
p = \(\frac{1600 * 25^2}{20}\)
p = 50,000 or 50 KW
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