Lamp A receives 100 J of energy and transfers 12 J of useful energy by light. Lamp B receives 50 J of energy and transfers 8 J of useful energy by light. Which lamp is more efficient?

Truck traveling west on the highway experiences an acceleration to the east. what could be the cause of this acceleration

Air is contained in a variable-load piston-cylinder device equipped with a paddle wheel. initially, air is at 400 kpa and 17°c. the paddle wheel is now turned by an external electric motor until 75 kj/kg of work has been transferred to air. during this process, heat is transferred to maintain a constant air temperature while allowing the gas volume to triple. calculate the required amount of heat transfer in kj/kg.

Match each scenario to the form of energy it represents