Physics paper 1

What is energy?

the capacity to do work

what is a system

An object or group of objects

how is energy transferred

Mechanically, electrically, heating, radiation

What happens when energy is transferred?

When energy is transferred some will go to a store and some will be is dissipated ( wasted energy )

What is specific heat capacity?

The amount of energy required to increase the temperature of 1kg of a substance by 1oC

How to calculate specific heat of regular object

1) calculate the mass by using a scale

2) he object by a electric heater

3) record the temperature on the thermometer

4) measure energy transfer

Q=Px T

Calculate the specific heat capacity of irregular object

1) measured mass with BALANCE

2) measure volume

3) heat object and submerge an object into a beaker with an unknown temperature

4) measure the temperature change

5) calculate energy transferred

What is the power

the rate at which work is done

What is conduction?

Transferring energies by vibrating particles neighbouring particles

What does conduction increase?

Kinetic energy and more collision

What is thermal conductivity?

A measure of how quickly energy is transferred through a material via conduction

If there is high thermal conductivity, what does that mean?

Higher conduction

What's the effect of thermal conductivity?

Higher thermal conductivity means faster heat transfer allowing faster cooling

Example of conduction

Thicker walls increase heat distance, allowing slower cooling

What is convection?

Where energetic particles move away from hotter to cooler regions

In what state of matter does convection happen?

liquids and gases

How to reduce energy transfer

Thermal conductivity of the insulator should be as low as possible.

Thickness of insulating material should be as much as possible.

What is lubrication?

A substance applied to reduce friction between moving parts ( energy transferred )

What is thermal insulation?

Cavity walls reduce energy transferred by conduction

Double glazed water holds to reduce energy transfer

Environmental impacts of fossil fuels

extraction, transportation, consumption

Acid rain

Environmental impacts of nuclear

Radioactive waste is produced

Environmental impacts of solar

Lots of energy and toxic material is produced

Environmental impacts of wind

HArms, animals and his noisy

Environmental impacts of hydro power

Destroys habitats

Environmental impacts of biomass

Habitat and biodiversity loss

Air pollution

Environmental impacts of geothermal

Cause earthquakes

Examples of non-renewable fossil fuels

Coal , oil gas

Examples of biofuels

biogas, bioethanol, biodiesel

examples of renewable fossil

Sun wind bio geothermal

What can renewable resources be used for in transport and heating?

Transport -biofuel

Heating -geothermal in heating pumps

How can nonrenewable resources be used in transport and heated?

Transport -petrol and diesel

Heating -natural gas pumped into radiators

What is the UK supply?

50 hertz

230 volts

What does the live wire do?

The live wire carries the alternating potential difference from the supply.

Brown

What does a neutral wire do?

Completes the circuit and carries away current

Blue

What does the earth wire do?

The earth wire is a safety wire to stop the appliance becoming live

Green and yellow stripes

What's a ohmic conductor?

-Has a constant temperature and directly proportional to the potential distance across the resistor

What happens in ohmic conductor?

Resistance is constant at the current increases

What happens to the resistance of components such as lamp style thermostat and LDS?

Resistance increases, but a small current for the potential difference

What happens to the current in a diode?

Resistance is reversed

What is radioactive decay?

Nucleus are unstable so gives out radiation to become stable

What is the rate of unstable decay measurement?

- activity in Bq

What is the count rate of a number of decay measured in?

Geiger muller tube

What does the alpha particle contain?

two protons and two neutrons

What is a beta particle contain?

High speed electron as neutrons turns proton t

What is a gamma particle?

an electromagnetic wave

What is alpha particle stop by?

Sheet of paper

Properties of alpha particles

Low penetration power (stopped by paper),

highly ionising

Properties of a beta particle

Negative charge of 1

Weak ionizing effect

Penetrates (stopped by few mm of Al/other metal)

Deflected by electric + magnetic fields

Properties of a gamma particle

Mass of 0, most penetrating power, least ionising power, neutral charge

What is half-life?

Life of a radioactive isotope is the time it takes for a number of nuclei to half

What type of process of radioactive decay?

Random

1/ half life is equal to

50 percent od a nuclei

What is 2 lives equal to?

25

If the activity at 80 seconds

After 10 minutes, it's 40 what's the half life?

10 mins

After 3 half lives 1/8remains how much is a decade?

7/8

What is radioactive decay contamination?

Unwanted presence of material contaminating radioactive atoms or other materials

Whats irridation

Process of exposure of nuclear radiation

How big is the atom?

1 x 10(-10)

How big is the radius of a nucleus?

It is less than 1/10,000th of the radius of the atom.

Radioactive contamination and irridation compare

Contamination-radioactive in an object but irritate is exposure not actually radioactive

Contamination has hazards even after radiation removed but irridation is only while exspeoed

Protection for contamination is protective clothing but for irridation is just distance

What's the importance of peer review and radiation?

-wrong conclusions can be dangerous

-Peer review insurance accuracy and reliability which increases Publix trust