Question

use the image to answer the question below. in the experimental setup shown, a car has one end of a string attached to it, and the other end is attached to a fixed number of metal discs. the car moves along the table and two probes sense the motion of the car. the probes send information to a computer that displays the acceleration and velocity of the experiment. when looking at these results, which quantity stays constant during the trials? (1 point)

Explanation:

In this experimental setup, the car's mass (or the total mass of the car - system, considering the car itself) remains constant during the trials. The number of metal discs is fixed, but the key constant quantity here is the mass of the car (or the system's mass excluding the discs' variable influence on force, but the car's own mass doesn't change). Another way: the mass of the car is a constant property here as the experiment focuses on the effect of the force from the discs (which could vary, but the car's mass stays the same) on acceleration/velocity. So the quantity that stays constant is the mass of the car (or the total mass of the car - system if we consider the car's mass as fixed).

Answer:

The mass of the car (or the total mass of the car - system, with the car's mass being constant) stays constant during the trials.