4. A box of mass M is pushed by a horizontal pushing force up a frictionless incline that makes an angle 3 with the horizontal. The box moves at constant speed. Find the magnitude P of the push ing force. 5. A child of mass 30kg is sliding down a slide that is inclined by 30. The coefcient of kinetic friction between child and slide is {1.2 Find the magnitude of the normal force, the maitude of the force of friction, and the child's acceleration. 6. A crate of mass lkg is at rest on a ramp that makes an angle of 15\" with the horizontal. How big is the force of static friction acting on the box