Which law describes the speed at which objects travel at different points in their orbits?

According to social exchange theory, altruistic behaviors benefit the individual who performs them. t/f

The image shows a pendulum in simple harmonic motion the pendulum starts at a and swing to e

Polly is pushing a box across the floor with a force of 30 n. the force of gravity is –8 n, and the normal force is 8 n. which value could describe the force of friction if polly could not move the box?