Contact Force - Definition, Examples, Quiz, FAQ, Trivia
Discover how forces work when objects touch each other!
What is Force?

Force is a push or pull that can make objects move, stop, or change direction. Forces are all around us! When you push a door open, pull a wagon, or kick a ball, you're using force. Forces can also make objects change shape or stay in place.
There are two main types of forces:
• Contact forces - when objects need to touch each other to create a force
• Non-contact forces - when objects can affect each other without touching
Force Fact!
Force is measured in Newtons (N), named after scientist Sir Isaac Newton. 1 Newton is about the force needed to hold a small apple!
Contact Forces

Contact forces happen when two objects physically touch each other. These are the forces you can feel and see in action every day. Here are the main types:
Applied Force
A push or pull directly applied to an object by a person or another object.
Example: Pushing a shopping cart
Normal Force
The support force exerted when an object rests on a surface.
Example: A book sitting on a table
Friction
A force that opposes motion between two surfaces that are touching.
Example: Brakes slowing down a bicycle
Tension
A pulling force transmitted through a string, rope, or wire.
Example: A swing hanging from chains
Spring Force
The force exerted by a compressed or stretched spring.
Example: A trampoline pushing you upward
Air Resistance
A type of friction that acts against objects moving through air.
Example: A parachute slowing a skydiver
Friction Fact!
Without friction, we couldn't walk! Friction between our shoes and the ground pushes us forward with each step.
Non-Contact Forces

Non-contact forces work without objects touching each other. These forces can act at a distance through fields. The main types are:
Gravity
The force that pulls objects toward each other. Earth's gravity keeps us on the ground.
Magnetic Force
The attraction or repulsion between magnetic materials.
Electrostatic Force
The force between electrically charged objects.
While non-contact forces don't require touching, they can still cause contact forces. For example, gravity pulls an apple down until it makes contact with the ground, where the normal force supports it.
Newton's Laws of Motion

Sir Isaac Newton described how forces work with his three laws of motion:
Law of Inertia
Objects at rest stay at rest, and objects in motion stay in motion unless a force acts on them.
Example: A soccer ball stays still until kicked
F = ma
Force equals mass times acceleration. Heavier objects need more force to move.
Example: Pushing a bicycle vs. pushing a car
Action-Reaction
For every action, there is an equal and opposite reaction.
Example: A rocket pushing gases down as it goes up
Newton Fact!
Isaac Newton developed his laws of motion when he was only 23 years old!
Force Quiz
Test your knowledge about forces with this 5-question quiz!
Frequently Asked Questions
Here are answers to common questions about forces:
Force Trivia
Discover some amazing facts about forces:
Feather vs. Hammer
On the Moon, where there's no air resistance, a feather and hammer fall at the same rate! Astronaut David Scott demonstrated this during the Apollo 15 mission in 1971.
Human Force Power
The strongest human punch ever recorded was by boxer Francis Ngannou - equivalent to 96 horsepower! That's like a small car engine packed into one punch.
Animal Force Champions
The tiny mantis shrimp punches with the acceleration of a .22 caliber bullet! Their club-like appendages move so fast they create shockwaves in water.
Space Friction
In space, friction still exists! Satellites experience atmospheric drag even in very thin upper atmospheres, gradually slowing them down over time.