Forces in Actions
Discovering the Science Behind Movement
What is Force?
Force is a physical concept that describes the
interaction between two objects that can change
the motion of one or both of them.
In simpler terms, force is a push or pull that can
cause an object to move, stop, or change direction.
Newton's 3rd Law: If an object A exerts a force on
object B, then object B must exert a force of equal
magnitude and opposite direction back on object A.
This law signifies a particular symmetry in nature:
forces always occur in pairs, and one body cannot
exert a force on another without experiencing a
force itself.
Types of Force
Contact Force Non-Contact Force
These are forces that act between These are forces that can act between
two objects that are physically two objects without them physically
touching each other. touching each other.
Contact Force Non-Contact Force
Friction Resistance Gravity Magnetic Force
The nuclear force
Electrostatic Force
Tension Applied Force
Contact Force 01
Friction
Friction is a force that happens when two surfaces rub
against each other. It's like a sticky force that can
make things harder to move smoothly.
Example:
Pushing a heavy box is harder than pushing a lighter box
because of friction between the box and the floor.
Contact Force 02
Resistance
Resistance is a force that happens when something
tries to slow down or stop another thing from moving.
Example:
A paraglider stays in the air because of air resistance.
The wind pushes against the paraglider and creates
the force.
Contact Force 03
Tension FOrce
Tension force is a type of force that happens when an
object is pulled in opposite directions by two forces.
Example:
Swinging on a swing creates tension in the ropes or
chains holding the seat up, keeping the swing suspended
and allowing the person to swing.
Contact Force 04
Applied Force
Applied force is when one object pushes or pulls on
another object. It happens when you use your muscles
to push or pull an object in a certain direction.
Example:
When playing soccer, a player uses their foot to push the
ball with force, making it move in the air. The harder the
player kicks the ball, the stronger the force they apply.
Non-Contact Force 01
Gravity
Gravity is a force that pulls objects towards each
other. It is what keeps us on the ground and what
makes things fall down.
Example:
When you jump on a trampoline, you come back down
because of gravity. Gravity is a force that pulls things
towards the ground.
Non-Contact Force 02
Magnetic Force
Magnetic force is a type of non-contact force that
acts between magnets or magnetic objects.
Example:
A magnet crane is a machine that uses a strong magnet to
pick up metal objects. When the magnet is turned on, it
creates a magnetic field that attracts the metal objects.
Non-Contact Force 03
Electrostatic
Electrostatic force is the force between two objects
that have an electric charge. Like charges repel,
opposite charges attract.
Example:
Lightning is caused by a build-up of electrical charge in
the air that suddenly discharges, creating a big flash of
light and loud thunder.
Let's Test it Out!
Identify what kind of force is used in the following illustrations.
Resource Page
Present Mode Keys
B for blur C for confetti D for a drumroll
M for mic drop O for bubbles Q for quiet
U for unveil 0-9 Any number from 0-9 for a timer
Force Measurement and Units
•SI unit for force is the Newton
•A Newton is a force that causes a 1kg mass to accelerate
at a rate of 1m/s/s. or 1m/s 2
2
•1 N (Newton) = 1 kg * m/s/s= 1kg*m/s
•We use a spring scale to measure force.
Mass and Weight
