"why did the solar nebula heat up as it collapsed? "

Study the following reaction carefully. what classification should this reaction have? 4al + 3o2 2al2o3synthesisdecompositionsingle replacementdouble displacement

Acompound machine is also called a machine. a. force b. simple c. complex d. directional

For the car in the picture ,in which direction is the normal force? -into the screen -down -out of the screen -up