Why do we need to study the concept of Equilibrium?

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.

The dot diagram represents the motion of the motorcycle as it moves from left to right

When a pair of 10-n forces act on a box of candy, the net force on the box is a 20 n. b about 14 n. c zero. d any of the above depending on the directions of forces.