White his the strongest of the fundamental forces? strong nuclear, weak nuclear, electromagnetic, gravitational?

Matter is needed to transfer thermal energy bya. conductionb. convectionc. radiation d. both a & b.

The number of passengers who arrive at the platform of a subway station for the 10 am train is a random variable with a mean of 120 and a variance of 16. find the lower bound of the probability that there will be between 100 and 140 passengers (round off to second decimal place).

What is the orbital period of a spacecraft in a low orbit near the surface of mars? the radius of mars is 3.4×106m.