Which of the following is the best definition of half-life for a radioactive substance? a. half of the amount of time required for all of the radioactive atoms to decay. b. the amount of time required for half of the radioactive atoms to decay. c. the amount of time required for each radioactive atom to decay halfway. d. all of the above.

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? 1. write the equation 2.list out your known variables 3.plug the numbers into the equations 4.solve 5.write your solution statement that includes initial energy and final

An electron is traveling with initial kinetic energy k in a uniform electric field. the electron comes to rest momentarily after traveling a distance d. (a) what is the magnitude of the electric field

Avoltaic cell converts chemical energy to