The diagram shows the movement of air as a result of convection currents. An illustration of a house with arrows in the clockwise direction. In the bottom left is a space heater. The arrows rising off the heater are labeled Y the arrows curving towards the ceiling are labeled W, the arrows going across the ceiling are labeled W and the arrows going down the wall on the opposite side of the room are labeled X.
At which point is the air at its highest density?

W
X
Y
Z

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.)

Convection occurs when thermal energy is transferred by the movement of

Abumper car with a mass of 250 kg is traveling at a speed of 4 m/s. this bumper car collides and sticks to a second bumper car with a mass of 250 kg, which is initially at rest. what is the final speed of these two bumper cars after the collision, assuming they remain stuck together?