"at the local high school, the baseball coach gives his players a punch on their ""workout punch card"" for every work out they complete outside of the regimen given by the coach. after a player gets 10 punches on the punch card, they are exempt from one early morning conditioning the next week. the punches on the punch card functioned as reinforcers."

In the situation explained above, the punches on the punch card functioned as positive reinforcers. This is because the punches on the punch card make it more likely for the players to individually complete work outs more regularly outside of the regimen given by the coach.

A. Elliptical orbits cause a planet to sometimes be closer to and sometimes farther away from the Sun.

Explanation:

The astronomer Johannes Kepler refined the Copernicus' heliocentric theory with the introduction of elliptical orbits with the formulation of his three laws of planetary motion, finally explaining why planets orbited the Sun at different speeds at different times, because prior to this, the heliocentric model used only circular orbits.

In this sense, the fact that planetary planetary orbits are elliptical was told by Kepler in the first Law of Planetary motion that states:

The orbit of a planet around the Sun, is in the form of an ellipse with the Sun at one of the two foci of that ellipse.