Forces(Physical world)
A force is anything that causes an object to change its shape,speed or direction of movement
Learning intentions:
1: define the term force 2:calculate force using the formula
3: describe contact and non contact forces
4: explain newton's 1st,2nd,3rd law of forces
5:describe the difference between mass and weight
6:define the term friction
7:explain balanced and unbalanced forces
8: illustrate and describe hooke's law
A contact force is a force that touches an object in order for it to change speed, shape or direction of movement.
A non-contact force is a force that does not touch an object in order to change its shape, speed or direction of movement.
Balanced and unbalanced forces
A balanced force does not move, as all forces acting on the object are equal and cancel each other out. if the force acting on an object are the same size, they will cancel each other out. Unbalanced forces are forces that do not cancel out, the object will move in the direction of the strongest force
Newtons first law: An object that isn't moving will not move and an object that is moving will stay moving. Newton's third law: For every action there is an equal and opposite reaction.
Calculation for force= mass x acceloration
Types of forces:
Non contact forces
Gravitational force– The force pulls an object towards the center of the planet- a falling marble
Magnetic force- the attraction and repulsion of magnetic materials when near a magnet a fridge magnet
Electrical force- the force between two electrically charged objects this can attract or repel- getting a shock
Contact forces
Mass: This is the amount of matter in an object
Weight:This is the downwards force of an object due to gravity
Friction– stops an object from moving or slows a moving object down- a rolling ball stops
Elastic force- if an elastic material is stretched or compressed it will try to return to its original shape– a stretched spring
Upthrust- the force of water pushing the molecules on the surface of a liquid to form a layer- a raindrop
Uplift- the force of air pushing an object–a plane in the air
Newtons second law The acceleration of an object is directly proportional to the strength of the force applied
Force (F)= mass(m) x acceleration
The greater the force the greater the acceleration; these are directly proportional
Newton's Third Law For every action there is an equal and opposite reaction.
Gravitational field strength- the force per unit mass, measure in newtons per kilogram (N/kg)
The more mass an object has, the greater this force will be
Gravity- a non contact force that pull two objects towards each other
Water resistance- the frictional force on an object as it moves through water
Air resistance- the frictional force on an object as it moves through air
Hooke’s law- a law stating that the extension of a spring is directly proportional to the force causing the extension
revision blooket to test you knowledge!
https://dashboard.blooket.com/set/662b7b7b350e9bc8ce18ab95