Without looking could you tell me.. How many pounds does a cubic feet of water have? How many BTUs do you need to heat 10x10x3 ft water pool 20 degrees F? Ho

Without looking could you tell me.. How many pounds does a cubic feet of water have? How many BTUs do you need to heat 10x10x3 ft water pool 20 degrees F? How much work in ft-lb is done by gravity when a 10 oz mass drops from 19 yards? How many HP are needed to rais 2400 lbs 74 inches in 30 sec? It is obvious you have 0 experience doing back-of-the-envelope calculations for scientific or engineering purposes. It is a no-contest between the metric and the imperial systems.