On a trip you travel at a constant speed of 50 kilometers per hour North for 1 hour. Then you turn West and travel at a constant speed of 40 kilometers per hour for 2 hours. Calculate your velocity for the trip. 43 km per hour
31 km per hour
27 km per hour West + 17 km per hour North
50 km per hour North + 40 km per hour West

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

Aperson stands on a platform, initially at rest, that can rotate freely without friction. the moment of inertia of the person plus the platform is ip. the person holds a spinning bicycle wheel with its axis horizontal. the wheel has moment of inertia iw and angular velocity ωw. take the ωw direction counterclockwise when viewed from above. part a what will be the angular velocity ωp of the platform if the person moves the axis of the wheel so that it points vertically upward?

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.