What is the efficiency of a car's engine when heat input is 400,000 joules and the waste heat is 300,000 joules?
O A. 85%
O B. 35%
C. 25%
D. 75%

What is hydroelectric power produced by?

The circles, or orbits, for electrons are called energy levels. each level can hold only a certain number of electrons. add electrons to each level until you can't add any more. how many electrons can each level hold?

Which of the following is the earliest era of earth's geologic time scale? cenozoic mesozoic precambrian paleozoic