Physics Yr.9

• heat definition 


  a flow of energy due to temp differences
• temperature


  the measure of hotness or coldness in a body.
• specific heat capacity


  how easy/hard it is to heat up an object
• specific heat capacity equation


  specific heat capacity = energy/ mass x change in temp
• amount of heat transferred equation

  amount of energy= power x time
• specific latent heat definition


  the amount of energy needed to change a substance of 1 kg without changing the temp.
• specific latent heat equation


  specific latent heat= energy/ mass
• fusion definition


  when solids change to liquids or liquids change to solids.
• sublimation definition


  when a gas changes to a solid.
• deposition definition


  when a solid changes to a gas
• wave definition


  an oscillation to transfer energy but not particles.
• longitudinal wave


  when the oscillation of the wave is parallel to the direction of energy transfer.
• transverse wave


  when the direction of energy transfer to perpendicular to the direction of energy transfer.
• period definition


  the time taken to complete 1 wave.
• specific heat capacity units


  J/kg°C
• Specific latent heat units


  J/kg
• Frequency definition


  the number of waves per second
• frequency units


  Hz
• frequency equation


  1/period
• 3 things that can happen to sound when it travels across a boundary


  -Reflected

  -Absorbed

  -Refracted
• How sound travels through the ear

  -outer ear catches waves

  -Waves vibrate the eardrum, which vibrates the hammer, anvil and stirrup.

  -This amplifies the waves and moves it to the cochlea, which is filled with fluid and stereo cilia.

  -These move back and forth in the waves, turning the waves into electrical signals.

  -These are transmitted to the brain through the auditory nerve.
• Speed all EM waves travel at

  3x 10 to the 8
• EM spectrum, longest to shortest wavelength

  Radio waves, Microwaves, Infrared, Visible light, Ultraviolet, X-rays, Gamma rays
• What is an alpha particle?

  A helium nucleus.
• What is a beta particle?

  A high- energy, fast-moving electron.
• What is a gamma particle?

  An electromagnetic wave.
• How does the Geiger- Müller tube work?

  When radiation enters, it colses the circuit of electrons, causing electricity to flow, which causes the device to click.
• Alpha decay description


  -Occurs in heavy elements, releasing an alpha particle from their nuclei makes them more stable.

  -Alpha particles have so much energy that they can bypass the electrons.
• Beta decay description


  -In the nucleus, a neutron turns into 1 proton and 1 electron.

  -The electron is emitted, but the proton remains in the nucleus.
• Half life is the time taken for a radioactive substance to reduce its activity by half.
• A photon is a packet of energy. All EM waves are made of photons. It is a particle but also behaves like a wave.