Question

In an experiment, students set up an inclined plane at an angle 8 on a horizontal lab table. The students release a block from rest on the inclined plane, and the block slides down the incline. The students record data for the time it takes the block to reach the bottom of the plane. This procedure is repeated five times, and the data are shown in the table. Which of the following claims could be supported by the experimental results? Trial Time (s) 1 1.25 2 1.35 3 1.41 4 1.51 5 1.59 A. buildup of dust between the block and the plane during each trial caused a decrease in the coefficient of kinetic friction between the two surfaces. B.The student placed the block closer to the bottom of the track during each subsequent trial, decreasing the final velocity. C. Each time the student placed the block on the inclined plane, the incline was pushed downward, decreasing the angle of the incline. D. Contact with the student's hand during the experiment caused the mass of the block to increase during each trial.

Answer 1

The claim that could be supported by the experimental results is that the buildup of dust between the block and the plane caused a decrease in the coefficient of kinetic friction.

Step-by-step explanation:

The claim that could be supported by the experimental results is option A. The buildup of dust between the block and the plane during each trial caused a decrease in the coefficient of kinetic friction between the two surfaces.

From the given data, we can observe that the time it takes for the block to reach the bottom of the plane gradually increases in each trial. This indicates that there is an increase in the sliding friction as the trials progress. The buildup of dust between the block and the plane can contribute to this increase in friction.

Therefore, option A, which suggests a decrease in the coefficient of kinetic friction due to the buildup of dust, is the most plausible claim based on the experimental results.

Answer 2

The experimental results showing increasing times for a block to reach the bottom of an inclined plane could be best explained by the inclined plane being pushed downward with each trial, reducing the angle of incline and thus the gravitational component driving the block down.

Step-by-step explanation:

In the experiment described, the time it takes for a block to slide down an inclined plane increases with each trial, which implies that the block is experiencing more resistance or a change in conditions over the course of the experiments. Considering the options presented and the physics of the situation, we can reason as follows:

• A: Buildup of dust could reduce friction, but this would likely cause the block to move faster, not slower, so this does not explain the increasing times.
• B: Placing the block closer to the bottom of the incline in each trial would result in a shorter travel distance, which could explain the increasing times; however, it's an unlikely action for consistent experiment setup.
• C: If the inclined plane is being pushed downward, decreasing the angle of incline, the gravitational component driving the block down would decrease, which could explain the increasing times to reach the bottom.
• D: The mass of the block is unlikely to change due to contact with the student's hand, so this would not be a valid explanation for the increasing times.

Therefore, the most plausible explanation supported by the experimental results is C, that each time the student placed the block on the inclined plane, the incline was pushed downward, decreasing the angle of the incline.