Heat is allowed to flow from the heat source of a heat engine at 425k to a cold sink at 313k. What is the efficiency of the heat engine? The answer should have three significant figures

An apple is falling from a tree. disregarding air resistance, which diagram shows the free-body diagram of the force or forces acting on the apple?

Copper has free electrons per cubic meter. a 71.0-cm length of 12-gauge copper wire that is 2.05 mm in diameter carries 4.85 a of current. (a) how much time does it take for an electron to travel the length of the wire? (b) repeat part (a) for 6-gauge copper wire (diameter 4.12 mm) of the same length that carries the same current. (c) generally speaking, how does changing the diameter of a wire that carries a given amount of current affect the drift velocity of the electrons in the wire?

When a light bulb shines, it gives off light energy and energy. a. heat b. potential c. chemical d. electrical