80.J of heat is injected into a heat engine, causing it to do work. The engine then exhausts 20.J of heat into a cool reservoir (i. e. wasted heat). What is the efficiency of the engine?

Complete the statement about memory improvement. ( )involves organizing and breaking down information into easier groups to expand capacity. rehearsal is the verbal repetition of information. these techniques are especially important for the improvement of ( ) memory.

Which are advantages of renewable resources? check all that apply. renewable energy supplies are completely reliable everywhere. some renewable resources will never be used up. little or no waste is produced by renewable resource plants. electricity can be generated in large quantities. many renewable energy facilities have lower operating costs.

Which best describes what forms in nuclear fission? a. two smaller, more stable nucleib. two larger, less stable nucleic. one smaller, less stable nucleusd. one larger, more stable nucleus