Two blocks 'P' and 'Q' on a smooth horizontal surface are shown in the given figures, (X) and (Y). Two forces of magnitudes 4 N and 5 N are acting in opposite directions on block 'P', while block 'Q' is moving with a constant velocity.

Which of the following statement is correct?
(a) 'P' experiences a net force and 'Q' does not experience a net force.

(b) 'P' does not experience a net force and 'Q' experiences a net force.

(c) Both 'P' and 'Q' experience a net force.

(d) Neither 'P' nor 'Q' experiences a net force.

(a) 'P' experiences a net force and 'Q' does not experience a net force.

Explanation: Block 'P' experiences two opposite forces of 5 N and 4 N. Since the forces are unequal, the net force acting on 'P' is:

$$5 - 4 = 1 \text{ N}$$

Therefore, block 'P' experiences a net force of 1 N.

Block 'Q' is moving with a constant velocity on a smooth horizontal surface. According to Newton's first law of motion, when an object moves with constant velocity, the net force acting on it is zero.

Therefore, 'P' experiences a net force and 'Q' does not experience a net force.