Physics Final Ka Year 10 Flashcards
What is the equation for density?
Density = mass ÷ volume
What do you find the volume of a regular shape?
Volume = L x W x H
What is the density of water?
1g/cm³
How do you find the density of an irregular shape?
Volume: Fill measuring cylinder with 100ml of water. Place object in water and measure the difference.
Mass: weigh the object.
Density: mass ÷ volume
Units - g/cm³
When measuring the density of an irregular object in water what does it mean when the object floats or sinks
If it floats it is less dense than water (below 1g/cm³).
If it sinks it is denser than water (above 1g/cm³).
What is the word for a solid turning into a gas?
Sublimation
Explain the particles in a solid, liquid and gas
Solid: there are strong forces holding the particles in a fixed pattern.
Liquid: some of the particles break and are less organised but they are still close together
Gas: the remaining bonds are all broken and the particles move randomly
Which state of matter can be compressed most easily?
Gas
Which state of matter do the particles have the most energy?
Gas
Do particles in a solid stay still?
No they vibrate
Explain shape and volume in the three states of matter
Solid: has a fixed shape and volume
Liquid: no fixed shape, fixed volume
Gas: does not have fixed shape or volume
Explain the internal energy
The internal energy is made up from the kinetic energy of the moving particles and the potential energy as bonds are stretched. Heating a solid increases it’s internal energy because the particles move further and faster. When the material changes the state we don’t lose any particles and so the mass stays the same.
Which particles leave the quickest when evaporation takes place
The most energetic ones
Why do you feel cold when you are wet?
Your skin is using energy to evaporate the water
What is an example of condensation?
When water molecules in the air from a liquid on a window
If the units of mass are kg, and the volume m³, what are the units of density?
Kg/m³
If the units of mass are g, and the volume m³, what are the units of density?
g/cm³
What is the latent heat of fusion?
The energy needed to change a solid into a liquid
What is the equation for energy (involving latent heat)
Energy = mass x specific latent heat of fusion
E= M x Lf
What is the units for latent heat of fusion?
J/kg
What is latent heat of vaporisation?
The energy needed to change a liquid into a gas
What is the equation for energy (including latent heat of vaporisation)
Energy = mass x latent heat of vaporisation
E= M x Lv
What are the units for energy?
J
The latent heat of fusion of a substance is 500J/kg. How much energy will be needed to melt 200g of it.
Energy = M x Lf
= 500 J/kg x 0.2kg = 100J