A50.0n box is at rest on a horizontal surface. the coefficient of static friction between the box and the surface is 0.50, and the coefficient of kinetic friction is 0.30. a horizontal 20.0n force is then exerted on the box. find the magnitude of the acceleration of the box

Aplayground slide is 8.80 ft long and makes an angle of 25.0° with the horizontal. a 63.0-kg child, initially at the top, slides all the way down to the bottom of the slide. (a) choosing the bottom of the slide as the reference configuration, what is the system's potential energy when the child is at the top and at the bottom of the slide? what is the change in potential energy as the child slides from the top to the bottom of the slide? (include the sign of the value in your answer.)