P6: Models and Explanations

P6: Models and Explanations

1. Density

   • Density (kg/m3) = Mass (kg) / Volume (m3)
   • Measuring Solids and Liquids
     • Measure the mass and volume of substance. To measure the mass, use a mass balance and to measure the liquid, pour it into a measuring cylinder.

2. Specific Heat Capacity

   • The energy needed to change the temperature of a material.
   • E.G. In an electric kettle, energy is transferred electrically from the mains to the thermal energy store. It's transferred by heating to the thermal energy store of the water, the water's temperature rises.
   • Change in Internal Energy (J) = Mass (kg) x Specific Heat Capacity (J/kgC) x Change in Temperature

3. Specific Latent Heat

   • The energy needed to change state.
   • Energy to Cause a Change of State (J) = Mass (kg) x Specific Latent Heat (J/kg)

4. Forces and Elasticity

   • When you apply force to an object it can be stretched, compressed or twisted but it can't go back to its original shape (deformed)
   • Force Exerted by a Spring (N) = Extension (m) x Spring Constant (N/m)
   • Energy Stored in a Stretched Spring (J) = 0.5 x spring constant (N/m) x (extension)2 (m)2