A1.98 kg mass is set on a spring, and the spring compression an amount 4.78 cm. what is the spring constant?

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.

4. if you were an astronaut on the moon, what would you experience? what would you see from your perspective?

Where do magnetic lines of force enter earth?