Galileo and newton both studied the night sky. galileo studied jupiter and its moons. newton studied the gravitational force that held the planets in orbit. which of these statements best explains why the two scientists proposed different theories about the solar system? both had limited data. both had different interests. they wanted to contradict each other's theory. they wanted to be the first to discover new planets.

Scientists use laser range-finding to measure the distance to the moon with great accuracy. a brief laser pulse is fired at the moon, then the time interval is measured until the "echo" is seen by a telescope. a laser beam spreads out as it travels because it diffracts through a circular exit as it leaves the laser. in order for the reflected light to be bright enough to detect, the laser spot on the moon must be no more than 1.0 km in diameter. staying within this diameter is accomplished by using a special large-diameter laser. part a if λ = 540nm , what is the minimum diameter of the circular opening from which the laser beam emerges? the earth-moon distance is 384,000 km. express your answer to two significant figures and include the appropriate units.

Mike walks 100 meter north, then walks 30 meters south. after this, he walks another 10 meters north. what is the magnitude of his total displacement during this walk,in meters?

Around faucet handle is part of a(n) a. lever b. screw c. inclined plane d. wheel and axle