Consider two bodies of weight W1 and W2 respectively connected by a light inextensible string as shown in fig,
Let the body W1 hang free and the W2 be places on an inclined smooth plane.
W1 will move downwards and the body W2 will move upwards along the inclined surface. A little consideration will show that the velocity and acceleration of the body W1 will be same as that of W2. Since the string is inextensible, therefore tension in both the string will also be equal.
Consider the motion of W1 W1 – T = (W1/g)a ...(1)
Consider the motion of W1
T – W2sin ± = (W1/g)a ...(2)
Solve the equations for ‘T’ and ‘a’