Internal energy & SHC

• What concept relates the internal energy of an object to its temperature?

  Specific heat capacity
• What is internal energy?

  It is the total energy stored by the particles making up a substance or system.
• What are the two parts of internal energy often discussed?

  Potential energy stores and kinetic energy stores.
• Which type of energy is important when heating a substance?

  Kinetic energy
• What happens to the kinetic energy of particles when a substance is heated?

  It increases, transferring energy to the kinetic energy store of the particles.
• How is temperature defined in relation to internal energy?

  Temperature is a measure of the average internal energy of a substance.
• Why do some materials require more energy to increase their temperature than others?

  Because they have different specific heat capacities.
• How much energy is required to warm one kilogram of water by one degree Celsius?

  4,200 joules
• How much energy is required to heat one kilogram of mercury by one degree Celsius?

  139 joules
• What is specific heat capacity?

  It is the amount of energy needed to raise the temperature of one kilogram of a substance by one degree Celsius.
• What happens when one kilogram of water cools by one degree Celsius?

  It releases 4,200 joules of energy to the surroundings.
• What is the equation for change in internal energy?

  Change in internal energy = mass × specific heat capacity × change in temperature.
• What does the symbol $\Delta$ represent in the equation for change in internal energy?


  It represents change.
• What does the symbol $\theta$ represent in the equation for change in internal energy?


  It represents temperature.
• How do you find the final temperature of a substance after energy has been transferred to it?

  By calculating the change in temperature and adding it to the initial temperature.
• What is the initial temperature of the water in the example given?

  20 degrees Celsius
• How much energy is transferred to the water in the example?

  20 kilojoules
• What is the specific heat capacity of water used in the example?

  4,200 joules per kilogram per degree Celsius
• What is the change in temperature for 800 grams of water after receiving 20 kilojoules of energy?

  5.95 degrees Celsius
• What is the final temperature of the water after the energy transfer?

  25.95 degrees Celsius
• Why might the temperature not increase as much in a real-life scenario?

  Because some energy would be lost to the surroundings, mostly as heat.
• What should be done to minimize energy loss during the experiment?

  Use a lid and insulate the container well.