A railroad engine coasting at 10 km/h runs into a stationary wagon. The engine weighs 5 times as much as the wagon. Assuming both of them couple together, how fast are they moving after the collision? Solve the problem and show all work.

Modify the equation fδt=δ (mv) to find the force of friction.

The magnitude of the amount of energy released by burning a fuel source, measured in energy per unit mass, is called its fuel value. note that the fuel value is the negative of the isobaric specific heat of combustion for the fuel. if all the energy obtained from burning 1.23 pounds of butane with a fuel value of 10.85 kcal/g is used to heat 128.0 kg of water at an initial temperature of 18.3 °c, what is the final temperature? note that 1 lb = 453.6 g.

What component of earth’s atmosphere exists entirely as a result of photosynthesis?