Question

If an object with mass m is moving at a speed of 5 ms - 1, the kinetic energy is 25 J, what will be its kinetic energy when its velocity doubles? A) 100N B) 100J C) 50N D) 50J​

Answer 1

Given :-

If  an object with mass m is moving at a speed of 5 ms - 1, the kinetic energy is 25 J,

To Find :-

KE when its velocity doubles

Solution :-

KE = 1/2mv²

25 = 1/2 × m × (5)²

25 × 2 = m × 25

50 = 25m

50/25 = m

2 = m

Now

New velocity = 2(5) = 10 m/s

KE = 1/2 × m × v²

KE = 1/2 × 2 × (10)²

KE = 1 × 100

KE = 100 J