In a nuclear reaction 5.02×10^-28kg of a radioactive sample reduced to 4.02×10^-29kg producing 259.74mev of energy. calculate the speed of the emmited radiation

Asun-sized star will spend most of its lifetime as a: white dwarf red giant protostar main-sequence star

What’s #16 asking and how do i solve it?

The magnitude of the poynting vector of a planar electromagnetic wave has an average value of 0.939 w/m^2 . the wave is incident upon a rectangular area, 1.5 m by 2.0 m, at right angles. how much total electromagnetic energy falls on the area during 1.0 minute?