RE-NEET Physics Work, Energy and Power Class 11 Questions

A particle of mass M moves along a horizontal x axis from x=0 to x=L. The coefficient of kinetic friction varies as a function of x as μₖ(x) = μ₀ - αx, where μ₀, α are constants of appropriate dimensions, so that μₖ(L) = 0. The total work done by the frictional force during the motion is ημ₀MgL, where g is the acceleration due to gravity. The value of η is:

An object moving along horizontal x-direction with kinetic energy 10 J is displaced through x = (3î) m by the force F⃗ = (−2î + 3ĵ) N. The kinetic energy of the object at the end of the displacement x is