A 40 kg block moves right with speed 1.5 m s⁻¹. It is acted upon by pulley forces F₁ and F₂ that vary with time as shown. Neglect friction and pulley masses. Find the speed of the block at t=12 s in m s⁻¹.

Question

G1 Physics · Accepted Answer

The block equation is 4F₁-F₂=ma. Evaluate a in each time interval from the force-time graph and update velocity. The velocity increments sum to 10.5 m s⁻¹, so v(12)=1.5+10.5=12 m s⁻¹.