A box of mass 8.0 kg slides at a speed of 10 ms⁻¹ across a smooth level floor before it encounters a rough patch of length 3.0 m. The frictional force on the box due to this part of the floor is 70 N. What is the speed of the box when it leaves this rough surface? What length of the rough surface would bring the box completely to rest?
Introduction This problem deals with the effect of friction on a moving object. When a box moves across a rough surface, the frictional force does negative work, reducing the speed of the box. We’ll apply the work-energy theorem to solve the two parts of this problem. Given Data Mass of box, m = 8.0 kg […]