100% satisfaction guarantee Immediately available after payment Both online and in PDF No strings attached
logo-home
GCSE/IGCSE Physics Summary Notes (A* Student) - Unit 3 Matter for CIE/ CAIE, AQA, Edexcel and OCR CA$9.52   Add to cart

Summary

GCSE/IGCSE Physics Summary Notes (A* Student) - Unit 3 Matter for CIE/ CAIE, AQA, Edexcel and OCR

  • Course
  • Institution

General physics, Thermal physics, Properties of waves, including light and sound, Electricity and magnetism, Atomic physics

Preview 2 out of 8  pages

  • January 17, 2023
  • 8
  • 2022/2023
  • Summary
avatar-seller
Temperature, pressure and volume
Brownian motion:
- Gas molecules move rapidly and randomly
- This is due to collisions with other gas molecules
- Massive particles may be moved by light, fast-moving molecules
- The temperature of a gas is related to the average kinetic energy of the molecules.
The higher the temperature, the greater the average kinetic energy
and so the faster the average speed of the molecules.
- Gases exert pressure on a container due to collisions between gas molecules and the wall. When
the molecules rebound off the walls, they change direction so their velocity and therefore
momentum changes. This means they exert a force because force is equal to the change in
momentum over time.
At a constant volume, if the temperature increases, the pressure increases because the molecules move
faster so they collide harder and more frequently with the walls - creating a force
At a constant temperature, if the volume increases, the pressure decreases because the molecules collide
less frequently with the walls.
- For a gas at fixed mass and temperature, 𝒑𝑽 = 𝒄𝒐𝒏𝒔𝒕𝒂𝒏𝒕 or P1V1=P2V2
(p is the pressure in Pascals and V is the volume in m3)
- It is inversely proportional (one decreases, the other increases)

, Evaporation
- Evaporation is the escape of molecules with higher energy from the surfaces of liquids.
- After they escape, the remaining molecules have a lower average kinetic energy which
means the temperature is lower (i.e. evaporation cools the liquid).
To increase the rate of evaporation:
- Increased Temperature: more higher energy molecules at the surface
- Surface Area: more molecules at the surface
- Draught: molecules are removed before returning to the liquid
Evaporation cools a body in contact with an evaporating liquid (i.e. skin with sweat on it)
because the liquid absorbs energy from the body so that it can continue to evaporate.




Thermal expansion
When something is heated, it expands because the molecules take up more space:
- When a solid is heated, the molecules vibrate more but stay in place, so the order of magnitude of
the expansion is small.
- When a liquid is heated, it expands for the same reason as a solid, but the
intermolecular forces are less so it expands more.
- When a gas is heated, the molecules move faster and further apart, so the relative
The order of magnitude of the expansion is the greatest.
Some applications and consequences of thermal expansion include:
- Railway tracks having small gaps so that they don’t buckle when they expand
- The liquid in a thermometer expands with temperature and rises up the glass
Prevent consequences
- leave gap for concrete roads, won’t crack
- Use then glass to hold hot water, won’t crack
- Put telephone wire sag high, won’t reach the floor


Thermal capacity
When the temperature of a body rises, its internal energy increases and its molecules vibrate more.
- The specific heat capacity is the amount of energy required to raise the temperature of 1kg of a
substance by 1°C.
𝑐h𝑎𝑛𝑔𝑒 𝑖𝑛 𝑡h𝑒𝑟𝑚𝑎𝑙 𝑒𝑛𝑒𝑟𝑔𝑦 = 𝑚𝑎𝑠𝑠 × 𝑠𝑝𝑒𝑐𝑖𝑓𝑖𝑐 h𝑒𝑎𝑡 𝑐𝑎𝑝𝑎𝑐𝑖𝑡𝑦 ×𝑡𝑒𝑚𝑝𝑒𝑟𝑎𝑡𝑢𝑟𝑒 𝑐h𝑎𝑛𝑔𝑒
∆𝐸 = 𝑚𝑐∆𝑇
where ΔE is the change in thermal energy inJ
c is the specific heat capacity in J/kg°C
m is the mass in kg
ΔT is the change in temperature in °C.

The benefits of buying summaries with Stuvia:

Guaranteed quality through customer reviews

Guaranteed quality through customer reviews

Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.

Quick and easy check-out

Quick and easy check-out

You can quickly pay through credit card or Stuvia-credit for the summaries. There is no membership needed.

Focus on what matters

Focus on what matters

Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!

Frequently asked questions

What do I get when I buy this document?

You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.

Satisfaction guarantee: how does it work?

Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.

Who am I buying these notes from?

Stuvia is a marketplace, so you are not buying this document from us, but from seller teeliianna. Stuvia facilitates payment to the seller.

Will I be stuck with a subscription?

No, you only buy these notes for CA$9.52. You're not tied to anything after your purchase.

Can Stuvia be trusted?

4.6 stars on Google & Trustpilot (+1000 reviews)

63613 documents were sold in the last 30 days

Founded in 2010, the go-to place to buy study notes for 14 years now

Start selling
CA$9.52
  • (0)
  Add to cart