"in softball, the pitcher throws with the arm fully extended (straight at the elbow). in a fast pitch the ball leaves the hand with a speed of 139 km/hr. (assume that the pitching motion originates with the arm straight back and terminates with the arm straight down. do not ignore gravity.) (a) find the rotational kinetic energy (in j) of the pitcher's arm given its moment of inertia is 0.720 kg · m2 and the ball leaves the hand at a distance of 0.604 m from the pivot in the shoulder. (enter the rotational kinetic energy of the pitcher's arm just after the ball is released.)"(b) what force (in n) did the muscles exert to cause the arm to rotate if their effective perpendicular lever arm is 4.00 cm and the ball is 0.187 kg? (enter the magnitude.) xn

The lights used by mark watley (played by matt damon) during the film the martian seem to be metal halide lamps. metal halide lamps are filled with vaporized mercury and metal-halogen compounds. when an electric current is passed through the lamp, the tube begins to glow a bright white/blue color. if you were to pass this light through a prism to separate the individual light frequencies, you would see a rainbow just as you would if using natural sunlight because of the complexity of the metal halide gas and the vast amount of possible electron transitions. (the study of light in this way is known as spectroscopy and allows astronomers to know exactly what atoms compose distant stars, simply by looking at the light they emit. the spectral lines an atom produces uniquely identifies that atom just like a fingerprint uniquely identifies a person. the momentum equation and energy equation that we have used above can be combined to give the following equation: c = e p where again p is the phonon momentum, e is the photon energy and c is the speed of light. when you divide the photon energy found in #6 by the photon momentum found in #4, do you get the speed of light? (if not, check your work for questions #4 through #6). yes no

The law of conservation of energy states that energy cannot be created or , energy can be from one substance to another. the first blank is ' destroyed ' and for the second blank is ' transferred '

Which one of the following terms is used to indicate the natural tendency of an object to remain at rest or in motion at a constant speed along a straight line? velocity acceleration equilibrium force inertia