Balanced and Unbalanced Forces

Which could be an example of an unbalanced force?

• A plate sitting on a dining table
• A ball at the top of a hill that is not moving
• Earth orbiting the Sun 
• A baseball that has been thrown to home plate.

Which could be an example of a balanced force?

• An asteroid moving at a constant speed through space 
• A car accelerating from a stop sign
• A box of dishes falling from a counter 
• A rocket taking off 

Which of the following objects will experience an unbalanced force?

• A bike rider on a smooth and level road, pedaling at a constant rate.

• A train pulling on another train, each with the same amount of force.

• A chair sitting on the floor with balanced forces acting in opposite directions.

• A ball rolling across the floor with friction acting in the opposite direction.

If these teams are pulling with the same amount of force what will happen?

• The boy in blue will win.
• They will not move at all.
• The boy in red will win.
• Both will fall down.

How will this object move? 

• It won't move. 
• It will move to the right. 
• It will move to the left. 
• It will move up. 

Which of the blocks above has balanced forces acting on it?

• A
• B
• C
• D

two forces acting in opposite directions on an object, and do not cause a change in motion; equal in size

• Force

• Balanced Force

• Unbalanced Force

• Inertia

two forces acting on an object and causes a change in motion; not equal in size.

• Force

• Balanced Force

• Unbalanced Force

• Net Force

An airplane is travelling North through the sky at a constant speed when turbulence causes it to take a different route, changing its direction. Explain the forces at work on this plane.

• Unbalanced, because the plane is moving forward, not backwards
• Unbalanced, because the speed is constant and there is a change in direction
• Balanced, because the plane is not falling to a lower altitude
• Unbalanced, because the plane is in motion

How will this object move? 

• It won't move. 
• It will move to the right. 
• It will move to the left. 
• It will move up.