You push forward on a book shelf with a force of 80 N and the shelf does not move at all (stays at rest). The force of friction acting on the bookshelf must be

World class speed skaters can skate a 3,000-m course in about 4 minutes.what is their average speed for this course? a. 12.5 m/sb. 1.33 m/sc. 1.25 m/sd. 13.3 m/s

If the force applied to an object remains constant, is more power needed for the object to move faster ? explain

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?