Physics - P1 Notes

Energy Stores and Systems

• Four energy stres are thermal, kinetic, gravitational potential and elastic potential
• As a ball is dropped, gravitational force does work. Energy is transferred from the ball's gravitational potential store to the kineti store
• Kinetic energy = 1/2 x m x v^2
• If energy is transferred to an object's kinetic energy store, it speeds up
• Gravitational potential energy = m x g x h
• When you compress a spring, energy is transferred to the elastic potential energy store

Specific Heat Capacity

• Specific heat capacity is the amount of energy needed to raise the temperature of 1kg of a material by 1 degrees
• change in thermal energy = mass(kg) x specific heat capacity(J/kgC) x temp. change (C)
• To find out the specific heat capacity of a material, you ca heat up a material and measure its temperature and current every minute for 10 minutes. Using the current and the potential difference to calculate the power

Conservation of Energy and Power

• Energy can be transferred usefully, stored or dissipated, but can never be created or destroyed. This means that whenever a system changes, all the energy is simply moved between stores
• Power is the rate of energy transfer (rate of…