Two students are investigating how balanced and unbalanced forces affect the motion of a small cart with freely rolling wheels. The students want to demonstrate three cases of motion:
no acceleration
acceleration to the left
acceleration to the right
The students use string to attach two spring scales to the cart so that the forces exerted on it can be measured in newtons (N), as shown in the figure. The cart is then released from rest.
Which set of forces will allow the students to demonstrate all three cases of motion?
To demonstrate all three cases of motion, the set of forces should include both balanced and unbalanced forces acting on the cart.
To have no acceleration, the forces should be balanced, meaning the forces on both sides of the cart are equal.
To have acceleration to the left, there should be an unbalanced force to the left that is greater than the force to the right.
To have acceleration to the right, there should be an unbalanced force to the right that is greater than the force to the left.
Therefore, the set of forces that will allow the students to demonstrate all three cases of motion is a combination of balanced and unbalanced forces.