A man of mass 80 kg is moving in the compartment of a train with a velocity of 10 ms^–1 eastward with respect to train frame. The train is moving with a velocity of 10 ms^–1 westward with respect to ground. The kinetic energy of a man in the ground frame in Joules is

Question

Question

This question was previously asked in

AP Police Constable (Prelims) Official Paper (Held On: 22 Jan 2023)

Answer 1

The correct answer is Option 1

Key Points

The velocity of the man with respect to the ground is calculated by adding the velocity of the man with respect to the train and the velocity of the train with respect to the ground.
The velocity of the man with respect to the ground is 0 m/s because the eastward and westward components cancel each other out.
Kinetic energy is calculated using the formula\( KE = \frac{1}{2}mv^2 \),
where v is the velocity of the object with respect to the ground.
As the velocity of the man with respect to the ground is 0 m/s, the kinetic energy is also 0 Joules.

Important Points

Relative velocity: The velocity of an object with respect to another frame of reference is known as relative velocity.
Ground frame: The frame of reference in which observations are made relative to the surface of the Earth.
Kinetic energy: The energy possessed by an object due to its motion is calculated by \(KE = \frac{1}{2}mv^2 .\)