A particle starts from rest, moves with constant acceleration for $15 \mathrm{s}$. If it covers $s_1$ distance in first $5 \mathrm{s}$ then distance $s_2$ in next $10 \mathrm{s}$, then find the relation between $s_1$ and $s_2$.

Calculate the acceleration of the system, tension in the string and thrust on the pulley in terms of g for the situation shown in following diagram.

Two blocks of masses 8kg and 4 kg respectively are connected by a string as shown. Calculate their accelerations if they are initially at rest on the floor, after a force of 100N is applied on the pulley in the upward direction (g = 10 m/s²)