A teenager is standing at the rim of a large horizontal uniform wooden disk that can rotate freely about a vertical axis at its center. The mass of the disk (in kg) is M and its radius (in m) is R. The mass of the teenager (in kg) is m. The disk and teenager are initially at rest. The teenager then throws a large rock that has a mass (in kg) of mrock. As it leaves the thrower's hands, the rock is traveling horizontally with speed v (in m/s) relative to the earth in a direction tangent to the rim of the disk. The teenager remains at rest relative to the disk and so rotates with it after throwing the rock. In terms of M, R, m, mrock, and v, what is the angular speed of the disk? Treat the teenager as a point mass.

Which best explains how a heat pump can heat a room? cold air from the house is moved through pipes, where it absorbs thermal energy. warm air from outside is pushed into the house to replace the cold air. combustion warms the air when chemical energy is transferred to thermal energy. fuel is used to move a piston, which pushes warm air into the house.

The graph below compares the rates of reaction of a burning candle and an exploding firework. comparing chemical reactions what can you conclude from the graph? the reaction that causes a firework to explode requires less energy to start, and occurs more rapidly than the reaction that causes a candle to burn. the reaction that causes a firework to explode requires less energy to start, and occurs less rapidly than the reaction that causes a candle to burn. the reaction that causes a firework to explode requires more energy to start, and occurs less rapidly than the reaction that causes a candle to burn. the reaction that causes a firework to explode requires more energy to start, and occurs more rapidly than the reaction that causes a candle to burn. mark this and return

What drives an advertising campaign?