As part of a lab experiment, Gar shoots a small stone straight
up in the air while his partner,
Grace, videotapes the motion
of the stone. The figure below
shows a plot of the stone's
position vs. time (air resistance i
ignored).
When is the stone moving the
fastest on the way up?

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?

Where do magnetic lines of force enter earth?

Two identical stars with mass m orbit around their center of mass. each orbit is circular and has radius r, so that the two stars are always on opposite sides of the circle. (a) find the gravitational force of one star on the other. (b) find the orbital speed of each star and the period of the orbit. (c) how much energy would be required to separate the two stars to infinity?