Determine the coefficient of friction of a 3.0-kg block that is being pulled across a table at a constant velocity with a force of 10.3 N.
(1) 0.35 (3) 0.48
(2) 0.17 (4) 0.52
5. What is the coefficient of friction of the block in problem #4 if the block is
accelerated at a rate of 2.0 m/s 2 with a force of 20.0 N?
(1) 0.48 (3) 0.12
(2) 0.59 (4) 0.85

As you are trying to move a heavy box of mass m, you realize that it is too heavy for you to lift by yourself. there is no one around to , so you attach an ideal pulley to the box and a massless rope to the ceiling, which you wrap around the pulley. you pull up on the rope to lift the box. use g for the magnitude of the acceleration due to gravity and neglect friction forces. once you have pulled hard enough to start the box moving upward, what is the magnitude f of the upward force you must apply to the rope to start raising the box with constant velocity? express the magnitude of the force in terms of m, the mass of the box.

An electron moves with a constant horizontal velocity of 3.0 × 106 m/s and no initial vertical velocity as it enters a deflector inside a tv tube. the electron strikes the screen after traveling 26 cm horizontally and 19 cm vertically upward with no horizontal acceleration. what is the constant vertical acceleration provided by the deflector? (the effects of gravity can be ignored.)

The diagram shows a boulder rolling down a hill into a valley and then up the opposite hill. at which position does the boulder have the greatest kinetic energy? ab c d