A man and his bike Are 95 KG. his instantaneous speed at one point is 14 m/s.. The next time he’s speed is checked he is going 28M/s. if his speed was taken 7 seconds later what force must the man have given his bike to change the speed?

Consider a small frictionless puck perched at the top of a fixed sphere of radius r. if the puck is given a tiny nudge so that it begins to slide down, through what vertical height will it descend before it leaves the surface of the sphere? [hint: use conservation of energy to find the puck's speed as a func e conservation of energy to find the puck's speed as a function of its height at what value of this normal force does the puck leave the sphere? ] here on the puck.