Which of these factors make hydrogen fuel cells a better option than burning fossil fuels? Hydrogen fuel cells have a higher energy efficiency. Hydrogen fuel cells create less pollution. Burning fossil fuels relies on outdated devices and technology. Hydrogen is the most abundant element in the universe. Hydrogen fuel cells are more expensive than fossil fuels.

An engineer designs a roller coaster so that a car travels horizontally for 162 ft, then climbs 127 ft at an angle of 31.0° above the horizontal. it then moves 127 ft at an angle of 46.0° below the horizontal. if we take the initial horizontal motion of the car to be along the +x-axis, what is the car's displacement? (give the magnitude of your answer, in ft, to at least four significant figures and give the direction of your answer in degrees counterclockwise from the +x-axis.)

In physics the desire of an object to keep doing what it is doing is termed?

Astone is dropped from a cliff and falls 9.44 meters. what is the speed of the stone when it reaches the ground? a. 13.6 m/sec b. 1.39 m/sec c. 185 m/sec d. 9.80 m/sec