Understanding Forces

What is an unbalanced force?

• A. A force that does not change an object's motion

• B. A force that is equal on all sides

• C. A force that causes a change in an object's motion

• D. A force that keeps an object at rest

When an object is not moving, what can you infer about the forces acting on it?

• They are balanced

• They are unbalanced

• There are no forces acting on it

• Only gravity is acting on it

If a soccer ball is at rest and someone kicks it, what type of force is applied?

• Balanced force

• Unbalanced force

• Gravitational force

• Magnetic force

Which of the following is an example of unbalanced forces?

• A. A book resting on a table

• B. A car stopping at a red light

• C. A person pushing a shopping cart that starts moving

• D. A picture hanging on a wall

What happens when two unequal forces act on an object in opposite directions?

• The object stays still

• The object moves in the direction of the smaller force

• The object moves in the direction of the larger force

• The object moves randomly

If a 10 N force is applied to a box from the right and a 5 N force is applied from the left, what will happen?

• The box moves to the left

• The box moves to the right

• The box does not move

• The forces cancel out

A car is moving forward. What force must act on the car to make it stop?

• A force equal to the car’s motion

• An unbalanced force acting in the opposite direction

• No force is needed

• A force moving in the same direction as the car

Which situation best represents unbalanced forces?

• A. A bicycle slowing down due to friction

• B. A person sitting on a chair

• C. A plane flying at constant speed

• D. A car parked on a hill with the brake on

Two people are pushing a box from opposite sides. One person pushes with 50 N of force to the right, and the other pushes with 30 N to the left. What is the net force?

• 0 N

• 20 N to the left

• 20 N to the right

• 80 N to the right

A rocket is launching into space. What force must be greater than gravity for the rocket to lift off?

• Air resistance

• Thrust

• Friction

• Balanced force