A 51.0 kg crate, starting from rest, is pulled across a floor with a constant horizontal force of 250 N . For the first 10.0 m the floor is frictionless, and for the next 11.0 m the coefficient of friction is 0.21. What is the final speed of the crate?

Amoving electron has kinetic energy k1. after a net amount of work w has been done on it, the electron is moving one-quarter as fast in the opposite direction. (a) find w in terms of k1. (b) does your answer depend on the final direction of the electron's motion?

The heliocentric and the geocentric models of the solar system included these central principles

Which of the following compounds would be primarily ionic? methane, ch4, ammonia nh3, calcium chloride, cacl2, or carbon dioxide, co2