Question

A block of mass 4 kg is placed on a rough horizontal plane. A time-dependent force F = kt2 acts on the block, where $k=2N/s^2$. Coefficient of friction μμ = 0.8. Force of friction between the n block and the plane at t = 2 s is

Answer 1

F = kt^2

F = 2t^2 --- k = 2

Fmax = μmg

= (0.8) (4) (10)

= 32 N

applied force = F = 2t^2

at t = 2s, F = 2 (2)^2 = 8N

Hence body cannot move.

And force of friction between block and plane = applied farce = 8 N