Ahomeowner is trying to move a stubborn rock from his yard. by using a a metal rod as a lever arm and a fulcrum (or pivot point) the homeowner will have a better chance of moving the rock. the homeowner places the fulcrum a distance =0.211 m from the rock, which has a mass of 325 kg, and fits one end of the rod under the rock's center of weight.
if the homeowner can apply a maximum force of 695 n at the other end of the rod, what is the minimum total length l of the rod required to move the rock? assume that the rod is massless and nearly horizontal so that the weight of the rock and homeowner\'s force are both essentially vertical.

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 heliocentric and the geocentric models of the solar system included these central principles

What distance does a car travel as its speed changes from 0 to 20 m/s in 17 s at constant acceleration?