Awater reservoir tank of capacity 250cubic metre is situated at height of 20m from the water level. what will be the power of an electric motor to be used to fill tank in the 3 hours? effeciency of motor is 70%.

Astudent creates a model of a closed ecosystem by filling a glass tank half full with water, then adding 10 snails and two small aquatic plants. the next day, all the snails are dead. what is the most likely cause of their death?

Amira pulls a 3 pound wagon 4 feet. how much work has she done?

A0.580-kg rock is tied to the end of a string and is swung in a circle with a radius of 0.500 meters. the velocity of the rock is 4.50 m/s. what is the centripetal force acting on the rock? 15.5 n 5.22 n 69.8 n 23.5 n