The speed of the bus increases from 10 to 20 m / s. What is the work of the resultant

The speed of the bus increases from 10 to 20 m / s. What is the work of the resultant of all the forces acting on the passenger of the bus weighing 80 kg?

V0 = 10 m / s.

V = 20 m / s.

m = 80 kg.

A -?

The work of the resultant force A is equal to the change in the kinetic energy of the body Ek: A = ΔEk.

ΔEk = Ek – Ek0.

The kinetic energy of the body Ek is determined by the formula: Ek = m * V ^ 2/2, where m is the mass of the body, V is the speed of movement of the body.

Since the passenger is on the bus, he also changes his speed, just like the bus.

Work A will be determined by the formula: A = m * V ^ 2/2 – m * V0 ^ 2/2 = m * (V ^ 2 – V0 ^ 2) / 2.

A = 80 kg * ((20 m / s) ^ 2 – (10 m / s) ^ 2) / 2 = 12000 J.

Answer: the resultant of all forces does work A = 12000 J.