a nurse pushes a woman in a wheelchair at a constant acceleration up a ramp for a period of 17.5 s. at the base of the ramp, the wheel chair is at rest, and at the top of the ramp, the wheelchair has a velocity of 0.50 m/s. the woman and her wheelchair have a combined mass of 65.0 kg. what is the magnitude of the net force on the woman and her wheelchair as they accelerate up the ramp?