What work must be done to increase the speed of a train weighing 800 tons from 36 to 54 m / s?

Initial data: m (mass of a given train) = 800 t (in SI m = 800 * 10 ^ 3 kg); V0 (initial speed) = 36 m / s; V (required speed) = 54 m / s.

We calculate the perfect work to increase the speed of a given train using the formula: A = ΔEk = Ek2 – Ek1 = 0.5 * m * V2 – 0.5 * m * V0 ^ 2 = 0.5 * m * (V2 – V0 ^ 2) …

Let’s perform the calculation: A = 0.5 * 800 * 10 ^ 3 * (54 ^ 2 – 36 ^ 2) = 648 * 10 ^ 6 J (648 MJ).

Answer: To increase the speed of a given train, it is required to perform work of 648 MJ.