Question

When the mass and velocity of the body are doubled what happens to its kinetic energy numerically?

Answer 1

See...kinetic energy formula is 1/2mv² say it is the initial kinetic energy before doubling...

Now after doubling mass and velocity, means that initial mass was m now became 2m and initial velocity was v² now became (2v)².....so now

kinetic energy=1/2 ×2m×(2v)²=1/2 × 2m ×4v²

So now just spearate 2 from mass and 4 from v and multiply we get 8 and rest left was 1/2mv² which is the initial kinetic energy.....

So conclusion is that the final kinetic energy becomes 8 times of initial kinetic energy after doubling mass and velocity of the body....

I hope it helps....