Question

Mr. Covault gave his students an assignment to design and conduct experiments that would allow them to find the relationship between force, mass, and acceleration. Some students decided to use a setup like the one below:

The applied force in this setup is equal to the weight of the item attached to the end of the pulley. One student tested the acceleration due to this force on a wooden block (as shown above); another student used a wheeled cart instead of a wooden block.

Mr. Covault's other students decided to simply drop objects. The force in that case is the weight of the object.

All the students measured the time it took each object, starting from rest, to move a certain distance. They used the time and distance to calculate the average acceleration.

Four students' results are shown below. A successful experiment should eliminate all forces acting on the object except the force being investigated. The experiment should confirm Newton's second law:



One newton (N) is 1 kg·m/s2.

Which of the following students had a well designed and conducted experiment?

Student Mass
(kg) Force
(N) Measured
Acceleration
(m/s2)
Kira 0.21 0.098 0.0047
Sophie 0.11 0.098 0.88
Jacques 0.050 0.49 4.9
Chase 0.50 4.9 8.9

Answer 1

Sophie

Step-by-step explanation:

Only Sophie's results supported Newton's second law. The other students' measured accelerations were significantly lower than expected. This could indicate that their experimental designs had not sufficiently eliminated drag forces.

F=ma Rearranging when solving for acceleration gives: a=F/m