A pen contains a spring with a spring constant of 257 N/m. When the tip of the pen is in its retracted position, the spring is compressed 5.1 mm from its unstrained length. In order to push the tip out and lock it into its writing position, the spring must be compressed an additional 6.1 mm. How much work is done by the spring force to ready the pen for writing

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?

True or false graphs must include scales that increase by the same amount

Aplane flying horizontally at an altitude of 1 mile and a speed of of 500mih passes directly over a radar station. find the rate at which the distance from the plane to the station is increasing when it is 2mi away from the station.