Physics- Energy and Power

what are the 2 main categories energy is divided into?

Kinetic energy and potential energy

what are the different types of energy

Kinetic energy, electrical energy, chemical energy, nuclear energy, thermal energy, light energy, elastic potential energy, gravitational potential energy, magnetic energy

how does a chemical reaction take place?

when bonds between the atoms break, energy is released

what is the law of conservation of energy

Energy can neither be created or destroyed, but only changed from one form to another

what is kinetic energy?

The energy of a moving object

how much kinetic energy does an object at rest have?

0

how does thermal energy flow?

from hot objects to cold objects

where is elastic potential energy stored?

in stretched or squashed materials

when is elastic potential energy released?

when a stretched object returns to its original shaoe and size

why may an object store gravitational potential energy?

due to its height above the ground

what does the amount of gravitational energy stored depend on?

the mass of the object, the height above the earth’s surface, gravitational field strength

where is chemical energy stored

in the bonds that connect atoms and molecules together

what is the most widely used type of energy in the world?

chemical energy

what is sound energy

a form of kinetic energy that is carried by the vibrations of particles moving through a medium

what is light energy

energy transferred by visible electromagnetic waves

what is electrical energy

a form of energy resulting from moving electric charges

where is nuclear energy stored?

in the nuclei of an atom

what is magnetic energy

the energy stored in a magnetic field

what is energy measured in?

joules

how do we calculate efficiency

(useful energy out/ total energy in)*100

when did the concept of energy emerge?

in the 19th century

what is power

the rate at which energy is transferred

what is work?

what is the equation for power in relation to the rate at ehich energy is transferd

power= energy transfered/ time

when does an object have an energy store

when it contains energy that can be transferred to other objects

how can energy be transferred?

mechanically, electrically, heating, radiation

what is a system?

an object or group of objects working together

what happens when a system is changed

energy is transferred

what occurs in an open system?

the matter can exchange energy with the outside world

What do the 4 pathways do?

describes the way energy moves from one store to another

in this image, chemical energy from the man’s muscles causes the box to move. Because of friction, it causes the box to heat up. What is the energy transfer?

chemical energy to thermal energy

Here, the man is transfering his energy to the box. Which of the 4 pathways does this use?

mechanical work

mechanical work

When something is moved using a force

electrical work

When electrical current flows, energy is transferred

heating

when something gets hotter

radiation

the process in which energy moves from one place to another in the form of waves or particles

What does it mean when a device has high efficiency?

when it can produce the same output energy with less input energy

what is the equation for work done

work done = force (newtons) * distance (metres)

what is energy measured in?

Joules

what is work the measure of?

energy transfer

how many jewels is 1 newtom-metre of work?

1 joule

what does a moving object have

a kinetic energy store

what are the different energy stores

thermal energy, gravitational potential energy, elastic energy, kinetic energy, electrostatic energy, chemical energy, nuclear energy

what can happen to an open system

it can loose or gain energy

what is kinetic energy

energy of movement

What is in the kinetic energy category?

thermal energy, radiant energy, sound energy, electrical energy

radiant energy

energy carried by electromagnetic waves as they travel through space

what is the equation for finding kinetic energy

kinetic energy = 0.5 × mass × speed²

provide the equation (algebraic) for finding kinetic energy

KE = 0.5 * mv²

how do we calculate gravitational potential energy

gravitational potential energy = mass x 9.8 N/kg x height (m)

what is the equation for power

power = energy transfered / time

what is the energy transfer of an object projecting upwards

Kinetic energy —> gravitational potential energy

what is the energy transfer for a moving object hitting an obstacle

Kinetic energy ➡ thermal energy, kinetic energy e.t.c

renewable energy

energy from a source that can be replenished

non-renewable energy

energy from a finite source that cannot easily be replaced

what happens when changes occur within a system?

there is 0 change in amount of energy

how is a gravitational energy store possessed

by an object due to its position above the ground in a gravitational field

what is the chemical energy store held in

chemical bonds

which energy transfer pathway is involved when a force moves an object

mechanical work

when boiling a kettle, energy is transfered from the electrical energy store to..

the thermal energy store

what do lumens measure

brightness or light output

what is the store where energy is stored in the nucleus of an atom

nuclear energy

if you placed a mass on a spring and released it, what is the energy store when the mass is added and when the energy store at the end (include pathway)

gravitational potential energy —> (mechanically) —> elastic potential energy

when you pull a car back and release, what is the Energy store when pulled back and the store when you release (include pathway)

elastic potential energy —>(mechanically) —> kinetic energy

what are the 8 energy stores

chemical, kinetic, thermal, gravitational potential, elastic potential, magnetic,eloctrastic, nuclear

in a complete circuit, what is the energy store in the batteries and what is the energy store when the circuit is complete (add the transfer)

chemical energy —> (electrically) —> thermal energy

electrostatic energy store

energy stored when repelling charges have been moved closer together or when attracting charges have been pulled further apart

by heating

Energy is transferred from a hotter object to a colder object because of a temperature difference

tell me the energy transfer in the lught bunsen Burner: energy store in the gas, energy store in the heated water

chemical energy —> (by heating) —> thermal energy

Throw the ball up

Energy store in the rising ball

Energy store in the high up ball

kinetic energy—>(mechanically )—>gravitational potential energy

Turn on the kettle

Energy store at the start

Energy store in the heated water

chemically—>(electrically) —> thermal energy

Inflate the balloon using the pump

Energy store in the inflated balloon

Energy store in the moving balloon

elastic potential energy —>(mechanically)—> kinetic energy

Turn on the radio

Energy store at the start

Energy store at the end

chemical energy —> (electrically) —> kinetic energy

what is the equation regarding efficiency in regards to energy

efficiency = useful energy output/total energy input

efficiency in regards to power

efficiency= useful power output/ total power input

when may someone me described as more powerful

if one person does the same amount of work as another but more quickly

what is the equation for power

work done/ time taken

what is power measured in

watts

What is 1 watt equal to?

1 joule per second

power

the rate of energy transfer

when is power higher

the faster the energy is transfered

what is the difference between energy and power

Energy is the total capacity to do work or the total work done and Power is the rate at which energy is transferred

what are the 4 common huge prefixes (in order)

kilo, mega, giga, terra

what is kilo worth

1000

what is giga worth

1 billion

what is terra worth

1 trillion

what is mega worth

1 million

what is the energy transfer of an object accelerating at a constant force

what is another way of saying energy transfered?

work done

dissipation

loss of energy until it dissapears

if i have a higher condiuctivity i will have…

a higher rate of transfer

Thermal conductivity

a materials ability to transfer heat