What is the ratio of the velocity of sound in helium gas to that in air at the same pressure and temperature? Molar mass of helium is 0.004 kg. = 1.66. On the basis of your answer, can you explain why you will sound funny if you happen to inhale helium gas and speak?

An engineer designs a roller coaster so that a car travels horizontally for 152 ft, then climbs 137 ft at an angle of 34.0° above the horizontal. it then moves 137 ft at an angle of 48.0° 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.)

The two required components for a generator

The diagram shows a series of volcanic island and a hot spot determine the direction of movement of the tectonic plate that for the island