The kinetic energy of a carriage moving at a certain speed is equal to 10,000 J.

The kinetic energy of a carriage moving at a certain speed is equal to 10,000 J. What will be the kinetic energy of a carriage if its speed increases threefold?

Given:

E1 = 10000 Joules – the kinetic energy of the car;

v2 = 3 * v1 – the speed of the car has increased 3 times.

It is required to determine E2 (Joule) – the kinetic energy of the car at increased speed.

Let m be the mass of the car.

Then, the kinetic energy of the car will be equal to:

E2 = v22 * m / 2 = (3 * v1) 2 * m / 2 = 9 * v12 * m / 2.

Taking into account that v12 * m / 2 = E1, we get:

E2 = 9 * v12 * m / 2 = 9 * E1 = 9 * 10000 = 90,000 Joules.

Answer: if the speed of the car increases by 3 times, the kinetic energy will be equal to 90,000 Joules (increase by 9 times).