A block of mass m = 2 kg moves along a horizontal surface with a coefficient of kinetic friction μk = 0.20. If the block maintains strict contact with the horizontal plane and there are no vertical external forces applied other than gravity, what is the normal force N exerted by the surface on the block? (Take g = 10 m/s2)

The tendency of an object to resist a change in its state of motion is called:

A box of mass 15 kg is kept on the floor of a stationary trolley. The coefficient of static friction between the box and the trolley is 0.12. To keep the box stationary relative to the trolley, the maximum horizontal acceleration (in m/s2) with which the trolley can move is: (g = 10 m/s2)