Sand falls vertically on a conveyor belt at a rate of 0.1 kg/s. In order to keep the belt moving at a uniform speed of 2 m/s, the force required to be applied on the belt is :

The force required to keep the conveyor belt moving at a uniform speed is calculated using Newton's Second Law of Motion in terms of momentum change. Since the mass is changing as sand falls on the belt, we use the formula for variable mass: F = d(mv)/dt.

Expanding this, we get: F = v(dm/dt) + m(dv/dt).

• Given that the belt moves at a uniform speed, the acceleration (dv/dt) is 0.
• The rate at which sand falls (dm/dt) is 0.1 kg/s.
• The constant velocity (v) is 2 m/s.

Substituting these values into the equation: F = 2 m/s × 0.1 kg/s = 0.2 N.

Therefore, a force of 0.2 N is required to maintain the uniform motion of the belt against the increasing mass of the sand. (Note: In the options provided, '0-2 N' represents 0.2 N).