The road train weighing 20 tons began to accelerate from rest. Determine the work of the traction force

The road train weighing 20 tons began to accelerate from rest. Determine the work of the traction force of the road train from the start of movement until the moment when its speed reaches 10 m / s. Determine the acceleration module of the road train, if by this moment it has traveled 100 m.

m = 20 t = 20,000 kg.

V0 = 0 m / s.

V = 10 m / s.

S = 100 m.

A -?

a -?

The work A of the traction force Ft of the road train is expressed by the formula: A = Ft * S, where S is the movement of the body under the action of the force.

m * a = Fт.

The acceleration of the road train a is expressed by the formula: a = (V ^ 2 – V0 ^ 2) / 2 * S.

Since the train starts moving from a state of rest, its initial speed is V0 = 0 m / s.

a = V ^ 2/2 * S.

a = (10 m / s) ^ 2/2 * 100 m = 0.5 m / s2.

Ft = m * V ^ 2/2 * S.

A = S * m * V ^ 2/2 * S = m * V ^ 2/2.

A = 20,000 kg * (10 m / s) 2/2 = 1,000,000 J.

Answer: the road train moves with an acceleration of a = 0.5 m / s2, the traction force does the work A = 1,000,000 J.