Question

A block of mass 3 kg slides down a smooth wedge as shown. String and pulley are ideal. If acceleration of wedge is 4 m/s². Find net force (in N) on block.

Answer 1

12 N

Answer 2

In the frame of the wedge, there is a pseudo-force acting on the block. The acceleration of the block relative to the wedge ($a_{b/w}$) is equal to the acceleration of the wedge ($a_w$) due to the constraint of the string and pulley system. The net force on the block is given by $F_{net} = m \times a_{b/w}$. Since $a_{b/w} = a_w = 4 \, \text{m/s}^2$, the net force is $3 \, \text{kg} \times 4 \, \text{m/s}^2 = 12 \, \text{N}$.