A mass of 1 kg is kept on an inclined plane with 30° inclination with respect to horizontal plane and it is at rest initially. Then the whole assembly is moved up with constant velocity of 4 m/s . The work done by the frictional force in time 2 s is _______ J. (Take g = 10 m/s ^2 )

Step-by-step solution

Since the assembly moves with a constant velocity, the acceleration of the mass is zero. The mass is in equilibrium relative to the incline. The frictional force f acting on the mass balances the component of gravity along the inclined plane. Therefore, the magnitude of the frictional force is: f = mg 30^ Substituting the given values ( m = 1 kg , g = 10 m/s ^2 ): f = 1 10 1 2 = 5 N The direction of the frictional force is upwards along the incline. Since the incline makes an angle of 30^ with the horizontal, the f