Motion Flashcards
What is the equation for density?
density = mass / volume
Density is measured in kilograms per metre cubed (kg/m³), mass in kilograms (kg), and volume in metres cubed (m³)
What can the particle model explain?
- Different states of matter
- Differences in density
The particle model describes how particles behave in solids, liquids, and gases.
What should students be able to do regarding the different states of matter?
Recognise and draw simple diagrams to model the difference between solids, liquids, and gases.
How can differences in density between states of matter be explained?
In terms of the arrangement of atoms or molecules.
What is the required practical activity to determine densities?
Use appropriate apparatus to measure and record the densities of regular and irregular solid objects and liquids.
What techniques are used to determine the volume of solids?
- Dimensions for regularly shaped objects
- Displacement technique for irregularly shaped objects.
What happens to mass during a change of state?
Mass is conserved.
What are changes of state?
Physical changes that differ from chemical changes and allow recovery of original properties if reversed.
What is internal energy?
The total kinetic energy and potential energy of all particles (atoms and molecules) in a system.
How does heating affect a system’s internal energy?
It increases the energy of the particles, raising the temperature or causing a change of state.
What factors affect the increase in temperature of a system?
- Mass of the substance heated
- Type of material
- Energy input to the system.
What is the equation for change in thermal energy?
ΔE = m c Δθ
Where ΔE is change in thermal energy (J), m is mass (kg), c is specific heat capacity (J/kg°C), and Δθ is temperature change (°C).
What is specific heat capacity?
The amount of energy required to raise the temperature of one kilogram of a substance by one degree Celsius.
What is latent heat?
The energy needed for a substance to change state.
What occurs during a change of state?
Energy supplied changes internal energy but not temperature.
What is the equation for energy required for a change of state?
E = m L
Where E is energy (J), m is mass (kg), and L is specific latent heat (J/kg).
What are the two types of specific latent heat?
- Specific latent heat of fusion - solid to liquid
- Specific latent heat of vaporisation - liquid to vapour.
What is the relationship between gas molecules’ motion and temperature?
The temperature of a gas is related to the average kinetic energy of its molecules.
How does changing the temperature of a gas at constant volume affect pressure?
It changes the pressure exerted by the gas.
What affects the rate of cooling of a building?
The thickness and thermal conductivity of its walls.
True or False: Thermal conductivity is defined in this context.
False.
