_is the force that acts between particles of different substances?

The of a machine determines its "usefulness." a. input force b. output force c. mechanical advantage

How is acceleration calculated? a. initial velocity - final velocity / timeb. initial velocity + final velocity / timec. final velocity - initial velocity / timed. final velocity / timele select the best answer from the choices provided0oood00save and exitnextmark this and return

Arunner is training for an upcoming marathon by running around a 100-m-diameter circular track at constant speed. let a coordinate system have its origin at the center of the circle with the x-axis pointing east and the y-axis north. the runner starts at (x, y) = (50 m, 0 m) and runs 2.5 times around the track in a clockwise direction.