Forces

what is a force

a force is the pushing or pulling of an object

What can forces do

makes things go faster, slower, change direction or shape

How are forces measured

forces can be measured using a spring blanence and mass is mesured using Newtons (N)

How mass affects acceleration

Objects with more mass require a larger force to accelerate, decelerate or change direction

Gravitational Force

acts between any two objects with mass. Gravity pulls objects towards the earth's centre

magnetic force

some metallic objects can be moved or infulenced without needing to directly touch

electrostatic force

a force of attraction or repulsion between objects that have built up charge.

Contact force: Applied forces

is a push or pull that is directly applied to an object

Contact force: Spring/ elastic forces

All materials have an amount of elasticity, however those with a large about of elasticity noticeably push or spring back after being stretched or compressed

Contact force: Normal force

the force that a surface applies to an object to support them. They are always acting at a right angles to the surface

Contact force: Tension forces

is tansmitted through a cable rope or wire when it is pulled tight from both sides

Resistive force

a force that oppose the movement of an object. They make things difficult to move and are responsible for slowing objects

Resistive force: friction

a force that opposes the movement of a stationary object

The more contact points the what?

The more contact points the harder

Resistive force: air/ water resistance

describes the resistances to objects moving through fluids. Particles in the air or water push against the object, slowing or stopping it

Balanced force

Both forces are applying the same amount of force, making the object stationary or move at a constant velocity if it is already moving and the resultant force is 0

Unbalanced Force

when there is more force being applied on one side than the other. In order for an object to move, it needs an unbalanced for acting on it

resultant force

When forces act in the same direction, they add to create a larger resultant force; when a force acts in opposite directions the resultant force is the difference in their sizes (or magnitudes) and acts in the direction of the larger force.

What is a free body diagram

a visual way of representing forces. The lengths of the arrows show the relative size of the force

kinetic friction

sliding friction; acts when an object is already moving

non contact forces

Appear to affect objects without touching them

What is gravity's common features

All objects with Mass have graviety

Every object has a gravitational attraction to every other object

Graviety is a non-contact force

How does mass and distance affect gravity

more mass means more gravitantonal pull. Further apart means less pull, closer togther means more pull

Obital speed

The speed at which an object travels in order to stay in constant orbit

gravitational feilds

every object with a mass has a gravitational feild pulling the object to the earth's centre. The closer you are to object, the stronger the gravitantional feild

Black hole

a collasped star with strong gravitational force that pulls everything near it

List the simple machines

lever, pulley, inclined plane, wedge, screw, and wheel and axle

Why do we use simple machines

they allow us to move ojects easier by:

producing a force in a different direction

reducing the effort needed to move an object

produce direction that is different to the applied motion

Effort force/ input force

amount of force required to lift an object

load force/ output force

the weight of the object being moved

how to find the mechanical advantage

dividing the load force by the effort force

Incline planes

helps spread a vertical climb over an angled distance so that less effort is required to move upwards

Wedge

consists of two inclined planes making a pointed end, effort force is applied downward to the wedge producing a load force outwards.

screw

inclined plane wrapped around a cylinder. you apply a turning force to the screw and the screw's thread converts this rotational motion into an forwards motion as it goes down

wheel and axle

when the wheel rotates, the axle rotates allowing teh force applied to the wheel to produce a greater turning effect

how does radius affect the wheel and axle

Force multiplier

a lever with an effort arm longer than the load arm mechanical ad in more than one

speed multiplier

a lever with an effort arm shorter than the load arm mechanical ad less than 1

Class 1

fulcrum in the middlem

class 2

load in the middle

class 3

effort in the middle