Download Forces - davis.k12.ut.us

A push or a pull on an object is
called a force.
Forces
Contact Forces
• A contact force is a push or a pull on one object by
another that is touching it.
• Contact forces can be weak or strong.
Normal Force
The normal force is the support force exerted upon an object
that is in contact with another stable object.
If a book is resting upon a surface, then the surface is exerting an
upward force upon the book to support the weight of the book.
https://www.youtube.com/watch?v=GmlMV7bA0TM
Applied Force
• An Applied Force is a force that is applied to an object by
a person or another object.
The Force of Friction
• Friction force is the force exerted by a surface as an object
moves across it or makes an effort to move across it.
• Friction depends upon the nature of the two surfaces and
upon the degree to which they are pressed together.
• The friction force often opposes the motion of an object.
• https://www.youtube.com/watch?v=MAqrWvkBoHk
Air Resistance Force
The air resistance is a special type of frictional force that acts
on objects as they travel through the air.
This force is most noticeable for objects traveling at high
speeds and those with large surface areas.
The Force of Tension
• The tension force is the force that is transmitted through a
string, rope, cable or wire when it is pulled tight by forces
acting on opposite ends.
• The tension force pulls equally on the objects on the
opposite ends of the wire.
Spring Force
• Spring force is the force exerted by a compressed or
stretched spring upon an attached object.
• The magnitude of the force is directly proportional to the
amount of stretch or compression of the spring.
Non-Contact Forces
• A non-contact force is a force that one object can apply
to another object without touching it.
These forces also have direction and strength.
Gravitational Force
• Objects fall to the ground because Earth exerts an attractive
force on them. This force is equal to the weight of the object.
• Gravity is an attractive force that exists between all objects that
have mass. The greater the mass, the greater the attraction.
• The closer the objects are, the greater the attraction.
• https://www.youtube.com/watch?v=6ZzfKKxbg7A
Electrical Force
• This is the force created between two charged objects or
particles. The objects either attract or repel each other.
• As distance increases, the electric force decreases.
• https://www.youtube.com/watch?v=XdA6zgLHPws
Magnetic Force
• This is the force that exists between two magnets, caused
by the interaction of their magnetic fields.
• This force causes the magnets to attract or repel one
another.
• https://www.youtube.com/watch?v=Mp0Bu75MSj8