Q. The needle of a sewing machine moves up and down in the same hermonic motion its driving force comes from a rotating wheel that is powered by an electric motor. how do you suppose that theup-and-down needle comapres with the period of the rotating needle?
Q. Two circus performers, Jack and Jill, whose total mass is 120 kg, start a swing which is 5.0 m long such that initially the rope attached to their swing makes an angle of 36 degrees with the horizontal. At the bottom of the arc, Jack, whose mass is 65 kg, steps off. What is the maximum height of a landing ramp that Jill can reach as the swing continues?