Why do nuclear power plants use fission rather than fusion to generate electric energy?
A. Fusion requires very high pressure and temperature.
B. A problem might lead to an explosion in a fusion reactor, but not
in a fission reactor.
C. The isotope used in fission is more common than the one used
in fusion.
D. Fission produces less radioactive waste than fusion does.

Aplayground slide is 8.80 ft long and makes an angle of 25.0° with the horizontal. a 63.0-kg child, initially at the top, slides all the way down to the bottom of the slide. (a) choosing the bottom of the slide as the reference configuration, what is the system's potential energy when the child is at the top and at the bottom of the slide? what is the change in potential energy as the child slides from the top to the bottom of the slide? (include the sign of the value in your answer.)