A weightless spring with a rigidity of 1000 N / m, compressed by 0.04 m, pushes a body with a mass of 0.01

A weightless spring with a rigidity of 1000 N / m, compressed by 0.04 m, pushes a body with a mass of 0.01 in the horizontal direction. what amount of mechanical energy will be converted into heat during the action of the spring on the body, if the body’s velocity has changed from 0m / s to 12m / s.

k = 1000 N / m.

x = 0.04 m.

m = 0.01 kg.

V0 = 0 m / s.

V = 12 m / s.

Q -?

According to the law of conservation of energy, part of the potential energy En of the compressed spring has passed into the kinetic energy of the body’s motion Ek, and part has passed into the internal energy Q.

En = Ek + Q.

Q = En + Ek.

The potential energy of the spring is determined by the formula: En = k * x ^ 2/2.

The kinetic energy of a body is determined by the formula: Ek = m * V ^ 2/2.

Q = k * x ^ 2/2 – m * V ^ 2/2.

Q = 1000 N / m * (0.04 m) ^ 2/2 – 0.01 kg * (12 m / s) ^ 2/2 = 0.08 J.

Answer: Q = 0.08 J of mechanical energy turned into internal energy.