Question

What work must be done to stop a bullet moving with a velocity of 2000ms^-1 and having a mass of 50g?

(a) 10^5J

(b) 10^6J

(c) 10^4J

(d) 10^7J

The question was asked by my college director while I was bunking the class.

I'd like to ask this question from Kinetic Energy in division Work, Energy and Power of Physics – Class 11

Answer 1

Right option is (a) 10^5J

The best I can explain: Work done against a body is the energy lost (kinetic) by it. Energy formula is 0.5*m*v^2. So, 0.5*(50/1000)*2000^2 = 10^5.