What equation represents the law of conservation of energy in closed system

Atank has a shape of a cone with a radius at the top of 2 m and a height of 5 m. the tank also has a 1 m spout at the top of the tank. the tank is filled with water up to a height of 2 m. find the work needed to pump all the water out the top of the spout. (use 9.8 m/s2 for g and the fact that the density of water is 1000 kg/m3.)

Abox is sliding on a frictionless surface when it suddenly begins to rain heavily. if the downpour of rainfall falls vertically into the box

Aweather forecaster uses doppler radar to predict the track of a storm near the town of meadowlands. when the doppler signal is pointed at the storm from the town's center, the frequencies of the waves appear to be decreasing. what should the weather forecaster predict? a. that the storm will move around the edges of meadowlands without hitting the tosis center o b. that residents should be prepared, because it is impossible to know whether the storm will hit o c. that the storm is moving toward meadowlands and that residents should be prepared d. that the storm is moving away from meadowlands and is not likely to hit the town