Balanced or Unbalanced?
A book is sitting still on a table. Are the forces balanced or unbalanced?
Balanced
What is "net force"?
The total force acting on an object
What is a contact force?
A force that requires physical contact to occur
What is a non-contact force?
A force that acts without touching the object
When you're riding in a car and it suddenly stops, you keep moving forward. Which law explains this?
Newton's First Law (Inertia)
A car speeds up on a highway. Balanced or unbalanced?
Unbalanced
If two people push a box in the same direction with 5 N each, what is the net force?
10N
Give one example of a contact force.
Friction, applied force, air resistance, normal force, tension force
Name a non-contact force.
Gravity, magnetism, electric force
A basketball won’t move unless someone picks it up or kicks it. Which law is this?
Newton's First Law
What happens to an object if forces on it are balanced?
It stays still or moves at a constant speed
If one person pushes with 10 N right and another with 4 N left, what is the net force and direction?
6 N to the right
What type of contact force slows down a sliding object?
Friction
What force keeps the planets orbiting the Sun?
Gravity
You throw a small ball and a heavy bowling ball with the same force. The small ball moves faster. Which law?
Newton's Second Law
Two students push a box from opposite sides with the same force. What type of force is this?
Balanced
How can you tell if the net force is zero?
The forces are equal and opposite; object doesn’t move or moves at a constant speed
When you push a door open, what kind of force are you using?
Applied Force
What kind of force makes a magnet pull on metal?
Magnetic Force
A rocket launches because gases push down, and the rocket moves up. What law is this?
Newton’s Third Law (For every action, there is an equal and opposite reaction)
Describe how an unbalanced force can change the motion of an object.
It can start, stop, or change the direction or speed of the object
Explain how to calculate net force when two forces act in opposite directions.
Subtract the smaller force from the larger one and keep the direction of the larger force
Describe how air resistance affects falling objects.
It slows them down by pushing against their motion
How can you tell a non-contact force is acting on an object?
The object moves or changes motion without being touched
You push a friend on a swing. They go forward, and you move slightly backward. Which law describes this?
Newton’s Third Law