(Tricky!) Suppose that a batter hits a foul ball almost exactly vertically in the air. As the ball rises, the magnitude of the torque that the gravitational interaction exerts on the ball around the pitcher:

Question

Quizplus · Accepted Answer

The torque ($\tau$) caused by gravity on the ball around a point (like the pitcher's mound) is given by $\tau = r \times F$, where $r$ is the distance from the point to the line of action of the force (in this case, the weight of the ball), and $F$ is the magnitude of the force (the weight of the ball, which is constant as it depends on mass and gravitational acceleration). As the ball rises vertically, the distance $r$ (horizontal distance to the pitcher) does not change, and neither does the force of gravity acting on the ball. Therefore, the torque remains roughly constant.

(Tricky!) Suppose That a Batter Hits a Foul Ball Almost