Astudent gets in an elevator and sets her backpack of mass m on the floor. the elevator accelerates upward with an acceleration a. (a) what is the normal force on her backpack? (b) now, she gives the backpack a kick, so that it has a speed v. it comes to rest a distance l from where it started. find the coefficient of kinetic friction between the backpack and the floor.

Acave rescue team lifts an injured spelunker directly upward and out of a sinkhole by means of a motor-driven cable. the lift is performed in three stages, each requiring a vertical distance of 10.0 m: (a) the initially stationary spelunker is accelerated to a speed of 4.90 m/s; (b) he is then lifted at the constant speed of 4.90 m/s; (c) finally he is decelerated to zero speed. how much work is done on the 68.0 kg rescue by the force lifting him during each stage?

In a series circuit the __ is the same at every point

3. a lunar exploration vehicle was created by a research team. it weighs 3,000 kg on the earth. it needs an acceleration of 10 m/s2 on the moon. in order to have the same acceleration, what will be the net force acting on the vehicle on the earth?