A man has mass 55 kg. His foot has the dimension of 24 cm×8cm. Find the pressure on his feet.

What happens to light waves from a star as the star moves away from earth?

What is relative velocity? in which condition is relative velocity known by adding the velocity of the first body and that of the second body

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?