science forces and electricity

ALL FORCES ARE MEASURED IN NEWTONS

How to measure torque

Torque has the unit Newton meters. (Nm) To calculate torque multiply the force by the length of the lever. (distance from pivot)

Torque = force x length

What are levers? levers are simple machines that make work easier. They work by using a rigid rod which rotates around a point/pivot called a fulcrum

What are pivots? Pivots are a fixed point from which an object will rotate/turn

weight is the force of gravity acting on an objects mass.

Mass is how much matter is in an object.

What is friction? Friction is a force that resists the relative motion between two objects in contact

What is static electricity? static electricity is the buildup of electrical charge on the surface of an object, usually caused by friction. Electrons are what allow static electricity to work.

What is electricity? electricity is a flow of charge around a circuit. Current is measured in Amps, amperes (A)

Electron transfer- electron transfer is when electrons move from one object to another due to contact, rubbing, electron movement and charge separation.

what is resistance? resistance is how difficult it is for electrons to flow through a wire, opposes the current. Measured in Ohms using an ohmeter.

Increasing and decreasing resistance-

-Increasing- thinner longer wire, heated wire, metals with greater resistance

-Decreasing- shorter, thicker wire, cool wire (slows electrons), metals with lower resistance.

SERIES/PARALLEL

In series circuits, the current (electrons) goes through all the components. It has a single loop or pathway. Components are connected one after another, and if one bulb goes out all bulbs go out. Ammeters are used in series circuits. In series circuits the current ALWAYS stays the same.

Unlike series circuits, parallel circuits components are connected are connected in separate branches, so the currents can flow through more then one path. When one bulb goes out, none of the other bulbs are affected because there are multiple branches for the current to reach. Voltmeters are in parallel circuits, placed parallel to the component being measured. In parallel circuits current is shared between branches but each branch is equal to the voltage of the power source.

Insulators vs conductors

Insulators do not readily allow the passage of electric current, whereas conductors allow the passage of electric current easily.

What is current? current is the flow of charged particles, current is measured in amps/amperes (A)

Voltage is the force supplied to the electrons by a power supply which pushes the electrons around the circuit. The higher the voltage the stronger the push and the more energy the electrons carry. Voltage is measured in Volts

Voltage = current x resistance V=IR

CONTACT VS NON CONTACT FORCES (add more)

contact:

-friction

-tension

-normal force

-applied force

Non contact:

-Gravity

-Magnetic force

-Electrostatic force

What are force diagrams? force diagrams show the direction and strength of a force acting on an object.

Gravity

Earths gravity is 9.8

How to calculate weight force.

Weight = mass x gravity Fw = m x g —> to find the weight force

SPEED

What is speed? Speed is the measurement is how fast something can cover a distance within a unit of time. Measured in meters per second (m/s) Distance/time = speed, Distance/speed = time, speed x time = distance

What is the relationship between force, mass and acceleration?

Newtons 2nd law F= m x a

The acceleration of an object depends on the net force acting on it and the mass of the object.
The greater the force, the greater the acceleration.
The greater the mass, the less acceleration for the same force.