A train has mass 250000 kg. Its motor accelerates the train to 25 m/s from a standing start in 45 seconds. The motor's power rating is 2.75 MW. How efficient is the motor?

Contains chemical energy. a. heat b. light c. natural gas

Why does karst topography exist in some geographic location? a. few climates have enough oxygen b. most regions have rock layers other than limestone c. in most regions, the soil is too thin d. the water is too acidic enough in most places

A10-kg piece of aluminum sits at the bottom of a lake, right next to a 10-kg piece of lead, which is much denser than aluminum. which one has the greater buoyant force on it? explain. b - the aluminum a) both have the same buoyant force. b) the aluminum c) the lead d) it cannot be determined without knowing their volumes.