Vector c is 6.28 m long in a 105 degree direction. vector d is 3.09 m long in a 233 degree direction. what is the magnitude and direction of their vector sum?

Why is alternating current more effective at long–distance travel than direct current? a. the power lines are made out of conductors. b. transformers increase or decrease voltage as needed. c. the ac generator is more efficient. d. ac has lower voltage than dc.

A2k pendulum has a speed of 1 m/s at a height of 1/2 meter

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.