JEE Main Physics question
The kinetic energy K of a particle moving in a straight line depends upon the distance s as K = as². The force acting on the particle is
Answer: (A)
Solution
K = ½mv² = as² ⟹ v² = 2as²/m. Differentiating with respect to s: 2v(dv/ds) = 4as/m ⟹ m(dv/dt) = m v(dv/ds) = 2as. The force F = ma = 2as.