A ball rolls at a constant 100 feet per minute as it approaches a hill. It then rolls down the hill gaining speed. At the bottom of the hill, it is going at 300 feet per minute. If it took 2 minutes to roll down the hill, then what is the distance from the top of the hill to the bottom of the hill?

Aproton is projected toward a fixed nucleus of charge +ze with velocity vo. initially the two particles are very far apart. when the proton is a distance r from the nucleus its velocity has decreased to 1/2vo. how far from the nucleus will the proton be when its velocity has dropped to 1/4vo?

An engineer designs a roller coaster so that a car travels horizontally for 162 ft, then climbs 127 ft at an angle of 31.0° above the horizontal. it then moves 127 ft at an angle of 46.0° below the horizontal. if we take the initial horizontal motion of the car to be along the +x-axis, what is the car's displacement? (give the magnitude of your answer, in ft, to at least four significant figures and give the direction of your answer in degrees counterclockwise from the +x-axis.)

According to newton’s first law of motion, which force is expected to cause a body to accelerate?