What is the mass of the skateboard? A 47.4 kg students runs down the sideral and jumps with a horizontal speed of 4.2 m/s onto a stationary skateboard. The student and skateboard move down the side walk with a speed of 3.95 m/s. Show work please

Assume that a person skiing high in the mountains at an altitude of h = 15100 ft takes in the same volume of air with each breath as she does while walking at sea level. determine the ratio of the mass of oxygen inhaled for each breath at this high altitude compared to that at sea level. assume that the air composition (i.e. % of air that is oxygen) is the same at sea level as it is at 15100 ft.

The energy equivalent of the rest mass of an electron is

Which form of cell division creates the sperm and egg, resulting in half of the chromosomes as the other cells?