Q. A physics professor is pushed up a ramp inclined upward at 30degrees above the horizontal as he sits his desk chair that slides on frictionless rollers. The combined mass of the professor and the chair is 90-kg. He is pushed 2.60-m along the incline by a group of students who together exert a constant horizontal force of 600-N. The professor speed at the bottom of the ramp is 1.75m/s. use the work-energy theorem to find out his speed at the top of the ramp.