Students are using the

Question

experimental setup shown in
the image in which the two
ends of a string are attached
to a car and to a hanger.
The students conduct three
trials in which they
place metal discs on the
hanger to manipulate the
force applied to the car. As a
result, the car
accelerates along the table
while two probes
collect motion data.
On the fourth trial of this
experiment, a student
places some discs on the
car by mistake. How would
this change the acceleration
or velocity?
(2 points)
In Comparison to the
third trial, when the
student adds discs
to the car instead of
the hanger, the mass
of the car is
decreased, which
will increase the
acceleration of the
car across the table.
In Comparison to the
third trial, when the
student adds discs
to the car instead of

Answer 1

the hanger, the mass of the system (car plus hanger) remains the same, but the distribution of mass changes. When the discs are added to the car, it increases the mass of the car, leading to an increase in the total mass of the moving system.

In comparison to the third trial, where the additional discs were placed on the hanger, the overall mass that the applied force (due to the hanging weights) has to overcome remains unchanged. With the increase in mass of the car, the acceleration of the car will decrease according to Newton's second law (F = ma), as the same force will now be applied to a heavier car.

In summary, adding the discs to the car instead of the hanger increases the car's mass, which results in a decrease in its acceleration compared to the third trial. The velocity of the car, assuming initial conditions remain similar, will also be affected; it will reach a lower maximum velocity due to decreased acceleration over time.