A man on a skateboard carrying a dictionary is initially at rest. He heaves the dictionary forward with a speed of 0.97 m/s and he recoils backward with a speed of 0.04 m/s. if the dictionary's mass is 3.24kg what is the mass of the man?

there are four types of friction: static, sliding, rolling, and fluid friction. static, sliding, and rolling friction occur between solid surfaces. static friction is strongest, followed by sliding friction, and then rolling friction, which is weakest. fluid friction occurs in fluids, which are liquids or gases.