Question

A tennis court official selects a random sample of 50 tennis balls that were slated for use in a highly contested match. He randomly assigns half of them to be subjected to 90 degree heat to replicate the presumed temperature at match time. The other half are run through a machine that replicates the action of hitting the ball 500 times. After the treatments, he inspects the balls for wear and tear.

Which of the following conclusions can we draw from this study?
A: We can make inferences based on the results of this study for the population of all tennis balls slated for use in the match.
B: We can draw conclusions about cause and effect for the population of tennis balls slated for use in the match.

Answer 1

The conclusion we can draw from this study is that we can make inferences based on the results of this study for the population of all tennis balls slated for use in the match.

Step-by-step explanation:

The conclusion we can draw from this study is option A: We can make inferences based on the results of this study for the population of all tennis balls slated for use in the match.

By randomly assigning half of the tennis balls to be subjected to heat and the other half to be hit by a machine, the study introduces controlled variables to replicate potential wear and tear scenarios that the balls might experience during the match. This allows us to make inferences about the population of all the tennis balls slated for use in the match based on the observed wear and tear after the treatments.

Answer 2

These experiments demonstrate physical principles such as the ballistic trajectory, rotational motion, and energy transfer during collisions. By observing the outcomes and changes made, such as marking the center of the string or changing the positions of a tennis ball and basketball during a drop, we gain visual and quantitative insights into these principles.

Step-by-step explanation:

In conducting the tennis ball experiments, we are observing the principles of physics in action. The observation outcomes are shaped by the laws of motion and energy conservation.

Experiment with Two Tennis Balls in a Ballistic Trajectory

By tying two tennis balls together with a string and throwing them in a ballistic trajectory, you will notice that the balls will follow a parabolic path, much like a single ball would. However, the string between them adds a rotational aspect to the motion, causing the pair to spin around each other.

When you mark the center of the string or attach a brightly colored sticker, it becomes easier to observe this rotational movement. You can see the sticker moving in an arc, giving a clearer visual representation of the rotational motion that occurs during the trajectory.

Experiment with a Tennis Ball and a Basketball

When you drop a tennis ball side by side with a basketball, they should both hit the ground at the same time, demonstrating that objects fall at the same rate regardless of mass if we neglect air resistance. If you drop the tennis ball on top of the basketball, the basketball transfers its energy to the tennis ball during the collision, which often results in the tennis ball bouncing much higher than it would on its own.

If you were to reverse the positions and drop the basketball on top of a tennis ball, the tennis ball would not significantly affect the bounce of the basketball due to the significant difference in mass and energy transfer potential.

Experiment with a Tennis Ball and a Racquet

In the bouncing tennis ball experiment, measuring the bounce height over a racquet both when it is stationary (stood on by you) and when held by a friend shows how the tension in the racquet strings impacts the bounce. A stationary racquet will absorb less energy during the collision, resulting in a higher bounce for the tennis ball. When your friend holds the racquet, it will likely absorb more energy and vibrate, reducing the bounce height of the ball and causing your friend's hand to move during the collision.