Forces
What is a force?
Push and pull
Towards body(pull)
Away from body(push)
What are the effects of a force?
Start/Stop motion of an object
Change size/shape of an object
increase/decrease speed of an object
Change direction of an moving object.
What are the different types of forces around us?
In contact
Friction
Elastic Spring force
At a distance
Magnetic force
Gravitational force
What is friction?
Exist between surfaces that
are rubbing against each other.
Friction opposes motion
Produces heat
How does friction affect us in our daily lives?
Positive
reduces slipping and sliding
(soles of shoes)
produces heat
(Match)
Allows us to control movement.
(vehicle Tires)
Negative
Causes wear and tear
Makes things over heat
Makes objects move slowly
How can we reduce friction?
Use lubricants.
Use rollers/ball bearings/wheels
streamlined body shapes
What is Elastic Spring force?
elastic objects change shape when a force is applied on it.
they return to their original shape when the force is removed
When a elastic object is stretched/compressed it exerts a force on the object stretching/compressing it called elastic spring force.
what is gravity?
Force of attraction on things that have mass.
Depend on mass of objects & distance between objects
What is magnetic force?
Attraction/repulsion
Example ( Maglev train)