Which statement best describes the difference between speed and velocity? a. velocity is speed with a direction. b. speed is velocity with a direction. c. velocity is acceleration with a direction. d. velocity measures position, while speed does not.

Free runners jump long distances and land on the ground or a wall. how do they apply newton’s second law to lessen the force of impact?

You are given a vector a = 125i and an unknown vector b that is perpendicular to a. the cross-product of these two vectors is a × b = 98k. what is the y-component of vector b?

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?