When a flask when full of air has a mass of 30.98 g. when the air is pumped out the flask has a mass of 30.72 g. find the mass of air in the flask before connecting to the vacuum pump

Which units can be used to measure length or distance? check all that apply. gram meter kilometer liter inch

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.)

Matter is needed to transfer thermal energy bya. conductionb. convectionc. radiation d. both a & b.