Question

You observe three carts moving to the left. Cart A moves to the left at nearly constant speed. Cart B moves to the left, gradually speeding up. Cart C moves to the left, gradually slowing down. Which cart or carts, if any, experience a net force to the left?

Short answer

Cart B experiences a net force to the left.

Step-by-step solution

Definition of Net force

The net force, also known as the resultant force, is the sum of all forces acting on an item at the same time.

Find that when there is a net force to the left, whichever cart or carts are it?

• Cart 'A' accelerates to the left at a near-constant rate.

• Cart 'B' accelerates as it advances to the left.

• Cart ‘C' moves to the left, swooping down gradually.

• The net force acting on an object moving at constant speed is zero, hence there is no net force acting on cart 'A' toward the left.

• When the item's velocity and force are in the same direction, the object will accelerate.

• Because the Cart B is speeding up and travelling to the left, there is a net force operating on the cart 'B' to the left.

• When the velocity and force directions are opposite, the item slows down.

• Because the cart C is slowing down and travelling to the left, there is a net force operating on the cart 'C' to the right.

Thus, the Cart ‘B’ is the cart that is being pushed to the left by the net force.