What is the most common source of pollution?
gas
nuclear
coal
oil

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.

Ihave a density of 1.61g/cm^3 and a mass of 28g. find the missing value

The force needed to overcome static friction is usually less than that needed to overcome kinetic friction.true or false?