A wheel has a constant angular acceleration of 1.9 rad/s2. During a certain 7.0 s interval, it turns through an angle of 63 rad. Assuming that the wheel started from rest, how long had it been in motion before the start of the 7.0 s interval?

Who was the first scientist to measure speed as distance over time?

Which of the following are guidelines to follow for obtaining accurate observations

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?