While exercising in a fitness center, a man lies face down on a bench and lifts a weight with one lower leg by contracting the muscles in the back of the upper leg. the weight has mass 13.5 kg, and is a distance of 28.0 cm from the knee joint. the moment of inertia of the lower leg is 0.900 kg⋅m2 , the muscle force is 1510 n , and its effective perpendicular lever arm is 3.60 cm. find the magnitude of the angular acceleration of the weight.

Moon effect. some people believe that the moon controls their activities. if the moon moves from being directly on the opposite side of earth from you to being directly overhead, by what percentage does (a) the moon's gravitational pull on you increase and (b) your weight (as measured on a scale) decrease? assume that the earth–moon (center-to-center) distance is 3.82 × 10^8 m, earth's radius is 6.37 × 10^6 m, moon's mass is 7.36 × 10^22 kg, and earth's mass is 5.98 × 10^24 kg.

The cerebellum controls? thirst sensations sleep-wake cycles hand-eye coordination heart rate and pulse

Why is the energy that results from a roller coaster's position at the top of a hill referred to as potential energy?