The Moon is about 400,000 km from the Earth. Using Newton's Law of Gravity how would the attraction between the Earth and Moon change if the distance from the Earth was halved to 200,000 km? 4 time weaker since it is two times closer 2 times stronger because it is twice as close 4 times stronger because it is twice as close 8 times stronger because of the inverse of 0.5 over 400,000 km

Water is siphoned from a large tank and discharges into the atmosphere through a 50-mm diameter tube. the end of the tube is b = 2.1 m below the tank bottom which is a = 7.4 m deep, and viscous effects are negligible. determine the maximum height h over which the water can be siphoned without cavitation occurring. atmospheric pressure is 101.4 kpa, and the water vapor pressure is 1.79 kpa (absolute)

Amoving electron has kinetic energy k1. after a net amount of work w has been done on it, the electron is moving one-quarter as fast in the opposite direction. (a) find w in terms of k1. (b) does your answer depend on the final direction of the electron's motion?

Does heating a metal wire increase or decrease its electrical resistance? why?