How much energy is transported across a 1.00 cm2cm2 area per hour by an EM wave whose EE field has an rms strength of 38.8 mV/mmV/m

What is the acceleration of a spaceship that is initially at rest and then speeds up to 220 m/s in 20 seconds

Which of the following correctly describes what happens when an atomic bomb explodes? small pieces of fissionable material are joined and form a body with a mass greater than the critical mass, the relative number of neutrons escaping decreases, and a chain reaction and explosion result. large pieces of fissionable matter are brought together quickly and form a body with a mass smaller than the critical mass, the relative number of escaping neutrons increases, and a chain reaction and explosion result.

Can any one me on number 4? i do know that it’s not a cause i gotten that wrong on the first try.