A rock is dropped in a pond, causing circular ripples. The radius increased with a rate 1 foot per second. When the radius is 4 feet, the area is increasing by 8π square feet per second.1. True2. False

In a heat engine if 1000 j of heat enters the system the piston does 500 j of work, what is the final internal energy of the system if the initial energy was 2000 j ?

Which sentences describe disadvantages of burning fossil fuels instead of using hydrogen fuel cells? burning fossil fuels contributes to climate change. burning fossil fuels takes place inside expensive fuel cells. fossil fuels aren't widely available, but pure hydrogen is. fossil fuels are nonrenewable.

The energy equivalent of the rest mass of an electron is