Achange occurs. when a material changes shape or size but composition does not change

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.

Find the momentum for a 2.6-kg brick parachuting straight downward at a constant speed of 8.4 m/s .

Although light from the sun appears white, it is actually made up of a lot of different colors. this portion of the electromagnetic spectrum, we call white light is referred to as within the electromagnetic spectrum.