A triangular block is moving horizontally with constant velocity v_0. A small block A of mass m is fixed on the triangular block. The work done by friction on the block A in time t will be

Q: A triangular block is moving horizontally with constant velocity v0. A small block A of mass m is fixed on the triangular block. The work done by friction on the block A in time t will be

Numerical

(a) zero

(b) -m g v0 t cos2 ⁡θ

(c) -m g v0 t sin2⁡ θ

(d) (-m g v0 t sin2⁡θ)/2

Ans: (d)