Two children push horizontally, but in opposite direction a box of 25 kg. The first children exert a force of 15 N to right and second children exerts a force of 20 N to left. The coefficient of between the box and surface is 0.3.

Arotating space station is said to create “artificial gravity”—a loosely-defined term used for an acceleration that would be crudely similar to gravity. the outer wall of the rotating space station would become a floor for the astronauts, and centripetal acceleration supplied by the floor would allow astronauts to exercise and maintain muscle and bone strength more naturally than in non-rotating space environments. if the space station is 200 m in diameter, what angular velocity would produce an “artificial gravity” of 9.80 m/s^{2} 2 at the rim?

Use the right-hand rule for magnetic force to determine the charge on the moving particle. this is a charge.

An isotope undergoes radioactive decay by emitting radiation that has a –1 charge. what other characteristic does the radiation have?