physics paper 1

what is a system

a system consists of either a single object or a group of objects

what is an open system

these can exchange energy and matter with their surroundings

example- your making coffee and you leave it then it cools down because of the heat escape

what is a closed system

they dont let energy or matter in or out .

in a closed system the total energy remains the same

what is energy measured in

measured in joules

what is the conservation of energy

which tells us energy can not be created or destroyed but only transfered from one store to another

what is the ways energy can be stored (8)

-thermal energy

-chemical energy

-kinetic energy

-gravitational potential energy

-elastic potential energy

-nuclear energy

-magnetic energy

-electrostatic enregy

what is theremal energy

the hotter an object is the more energy in its thermal store

what is chemical energy

releases energy due to a chemical reaction

• found in batteries and fuels

what is kinetic energy

energy of moving objects

what is gravitational potential energy

Energy stored due to an object's height in a GRAVITATIONAL FIELD.

what is elastic potential energy

stored when objects are stretched or squashed

what is nuclear energy

released during nuclear reactions

what is magnetic energy

due to attraction or repulsion between magnets

what is electrostatic energy

due to attraction or repulsion between charged particles

what are the types of energy transfers (4)

-mechanical work

-heating

-electric work

-radiation

what is mechanical work

when force is applied

what is heating in energy transfer

transfer of enrgy from a hot object to a cold object

what is electric work in energy transfers

when current flows in a circuit and transfers energy

what is radiation in energy transfer

energy is transferred in the form of a wave

what is mass measured in equations

kg

what is speed measured in

metres per second

m/s

what is elastic potential energy measured in

joules

what is spring constant

measures how stiff the object being stretched is and measured in newtons per metre n/m

what is the gravitational field strength

9.8

the higher the object then what is gpe like

the higher the object the greater the gpe

when is there a change in energy

whenever you heat up or cool down an object theres a change in energy

what is specific heat capacity

the specific heat capacity tells us how much heat energy (in joules) is needed to raise the temperature of 1kg of substance by 1 degree celius.

• how easy it is for a material to heat up or cool down

what equipment is needed for the expirement to measure specific heat capacity

• METAL BLOCK: Made of the material you are testing, like aluminium, with holes for the heater and thermometer.

• IMMERSION HEATER: To provide heat to the metal block.

• THERMOMETER: To measure the temperature of the metal block.

• INSULATION: To minimise heat loss from the metal block.

• JOULEMETER: To measure the amount of energy used.

• MASS BALANCE: To measure the mass of the metal block.

• BATTERY PACK: To supply power to the immersion heater

what is the method to measure specific heat capacity

PROCEDURE

1. MEASURING MASS:

   • Use the MASS BALANCE to measure the mass of the metal block. Record the value.

2. SETTING UP THE EXPERIMENT:

   • Place the metal block into insulation and insert both the IMMERSION HEATER and THERMOMETER into the appropriate holes in the block.

   • Connect the IMMERSION HEATER to the BATTERY PACK and the JOULEMETER.

 

1. HEATING AND MEASURING:

   • Turn on the IMMERSION HEATER to start heating the metal block.

   • Record the initial temperature from the THERMOMETER and the initial energy from the JOULEMETER.

2. CALCULATING SPECIFIC HEAT CAPACITY:

   • Once you have finished heating, turn OFF the heater.

   • Record the final temperature and energy readings.

   • Use the SPECIFIC HEAT CAPACITY equation.

what is power

power is the rate at which energy is being transferred or work is being done

what is power measured in

watts

what is time measured in

seconds

what does high power mean

it transfers energy at a fast rate

what is dissipation

the energy that is wasted

what happens when a phone vibrates

Energy moves from the CHEMICAL energy store of the battery, ELECTRICALLY, to the KINETIC energy store of the phone's motor, causing it to vibrate.

how to reduce unwanted energy transfers to maximise efficiency and minimise costs

• cavity walls

• loft insulation

• double glazing windows

• draught excluders

how does lost insulation reduce energy loss

• made from materials with low thermal conductivity

• reduces energy loss through conduction and conection

when does convection occur

when liquids and gases are able to move and transfer heat

how does double glazing windows reduce energy loss

By having two layers of glass with trapped gas between them, these windows lessen energy loss due to CONDUCTION and CONVECTION.

how can you minimise frictional forces on a bike

• lubrictae chain with oil

what is efficiency

Efficiency is a ratio of the amount of useful energy that’s given out to the total amount of energy that was originally put in.

what is the formula for efficiency

how can you improve efficiency

• by reducing wasted energy transfers

what is energy mainly wasted on

• Friction between their moving parts

• Air resistance

• Electrical resistance

• Sound

=most of these lead to thermal energy being disspicated to the surroundnings

what are the 2 types of energy resocurces

renewable and non renewable