Assume all other forces on Barbara are balanced. Which statement describes the forces on Barbara?
The forces are balanced, so there is no net force on Barbara. The forces are unbalanced, so there is a net force on Barbara.
Barbara is sitting on a roller coaster cart as it reaches the bottom of a big loop. Earth's gravity is pulling down on Barbara with a force of 600N. The seat of the cart is pushing up on Barbara with a force of 1,200N.
A force is a push or a pull that acts on an object. Every force has a direction and a magnitude, or strength. If two forces act on an object in opposite directions, the forces are called opposing forces.
When opposing forces have the same magnitude, they are balanced. If all the forces on an object are balanced, there is no net force on the object.
When opposing forces have different magnitudes, the forces are unbalanced. If any forces on an object are unbalanced, there is a net force on the object.
To determine if there is a net force on Barbara, look at the forces:
Earth's gravity is pulling Barbara down with a force of 600 N.
The seat of the cart is pushing Barbara up with a force of 1,200 N.
The forces are in opposite directions, and the forces have different magnitudes: 600 N and 1,200 N. This means that the forces are unbalanced, so there is a net force on Barbara.