A heat engine exhausts 3000 J of heat while performing 1500 J of useful work. What is the efficiency of the engine

When considering gravity acceleration and the force of acceleration, what must be true? a. the direction of acceleration must be perpendicular to the direction of the force. b. the direction of the force and the direction of acceleration must be the same as each other. c. the direction of the force and the direction of acceleration must be opposite of each other. d. the mass of the body must be the same as the acceleration of the body.

Atelevision set that has been running for a while heats up even the air around it. which two laws of thermodynamics could be used to analyze this scenario

Acar drives toward the right over the top of a hill, as shown below. which arrow represents the centripetal acceleration? w x y z