A child sitting 1.90 m from the center of a merry-go-round moves with a speed of 2.05 m/s . Calculate the centripetal acceleration of the child. Calculate the net horizontal force exerted on the child. (mass = 28.5 kg ).

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 the first law of thermodynamics, triangle e=q-w, what does q stand for

The air that we breath is made mostly of which gaseous molecule