Apile driver lifts a 450 kg weight and then lets it fall onto the end of a steel pipe that needs to be driven into the ground. a fall of 1.5 m drives the pipe in 45 cm.
what is the average force exerted on the pipe?

Name three different units of energy used to measure heat and describe what type of situations each is usually used.

Which of the following are considered noble gases? a. bromine b. neon c. argon d. chlorine

Suppose water is leaking from a tank through a circular hole of area ah at its bottom. when water leaks through a hole, friction and contraction of the stream near the hole reduce the volume of water leaving the tank per second to cah 2gh , where c (0 < c < 1) is an empirical constant. a tank in the form of a right-circular cone standing on end, vertex down, is leaking water through a circular hole in its bottom. (assume the removed apex of the cone is of negligible height and volume.) (a) suppose the tank is 20 feet high and has radius 8 feet and the circular hole has radius 2 inches. the differential equation governing the height h in feet of water leaking from a tank after t seconds is dh dt = − 5 6h3/2 . if the height of the water is initially 8 feet, how long will it take the tank to empty? (round your answer to two decimal places.)