Physics

• What is the unit of measurement for energy?

  Joules (J).
• What does it mean that energy can never be created or destroyed?


  Energy can only be transformed from one form to another.
• What is the total amount of energy in a closed system?

  The total amount of energy remains constant.
• What are the different types of energy stores mentioned?

  1. Magnetic
  2. Internal
  3. Chemical
  4. Kinetic
  5. Electrostatic
  6. Elastic potential
  7. Gravitational potential
  8. Nuclear
• What happens to the energy of a ball as it falls?

  Gravitational energy is converted into kinetic energy.
• What is the formula for kinetic energy?


  Kinetic energy is given by $E =$$\frac{1}{2} m v^2$.
• What happens to kinetic energy if the mass is doubled while keeping velocity constant?

  The kinetic energy doubles.
• What happens to kinetic energy if the velocity is doubled while keeping mass constant?

  The kinetic energy increases by four times.
• What is the formula for elastic potential energy?

  Elastic potential energy is given by $E =$$\frac{1}{2} K e^2$.
• What does the spring constant measure?

  The spring constant measures how stiff the spring is.
• What is the formula for gravitational potential energy?


  Gravitational potential energy is given by $E =$$m g \Delta h$.
• If a block of mass 5 kg is raised to a height of 10 m, what is its gravitational potential energy?

  The gravitational potential energy is $500 \text{ J}$.
• What is specific heat capacity?

  Specific heat capacity is the energy required to change the temperature of 1 kg of a substance by 1°C.
• What is the specific heat capacity of water?

  4,200 J/kg°C.
• What does a higher specific heat capacity indicate about a material?

  More energy is required to change its temperature.
• What is the formula for calculating energy using specific heat capacity?

  Energy is given by $E =$$m c \Delta \theta$.
• How do you calculate the energy transferred when heating water from 5°C to 45°C with a mass of 100 g?


  The energy transferred is $1,680 \text{ J}$.
• What equipment is needed to determine the specific heat capacity of an aluminum block?

  • Heater
  • Thermometer
  • Voltmeter
  • Ammeter
  • Power supply
  • Stopwatch
  • Aluminum block
• What is the formula for calculating energy transferred using current and voltage?

  Energy is given by $E =$$I \cdot T \cdot V$.
• What is the unit of power?

  Watts (W).
• What is the relationship between power, energy transferred, and time taken?

  Power is the rate at which energy is transferred.
• If a hair dryer transfers 1,000 J in 20 seconds, what is its power?

  The power is 50 W.
• How is energy efficiency calculated?

  Efficiency is calculated as $\text{Efficiency} =$$\frac{\text{Useful energy out}}{\text{Total energy in}} \times 100$.
• If a light bulb has 100 J of energy input and 80 J of useful output, what is its efficiency?

  The efficiency is 80%.
• What is thermal conductivity?

  • The ability of a material to conduct heat.
  • Higher thermal conductivity means more heat can flow through.
  • Affects the rate of cooling.
• Which material has the highest thermal conductivity?

  Glass.
• What is the aim of the practical investigating thermal insulation properties?

  • To determine which insulation loses heat at the fastest rate.
  • Use different types of insulation around beakers.
  • Record temperature changes over time.
• What is the control variable in the thermal insulation practical?

  The type of insulation used must remain constant.
• What is the aim of the second part of the thermal insulation practical?

  • To investigate how thickness affects thermal insulation properties.
  • Use the same type of insulation with varying thickness.
  • Record temperature changes over time.
• What is the relationship between the thickness of insulation and thermal conductivity?

  Thicker insulation generally reduces heat loss.
• What is the formula for calculating the gradient of a temperature vs. energy graph?

  The gradient is calculated as $\Delta \theta / \Delta E$.
• How can the specific heat capacity be determined from the practical results?

  It can be determined by rearranging the formula $E =$$m c \Delta \theta$ to find $c =$$\frac{E}{m \Delta \theta}$.
• What is the significance of the gradient in the specific heat capacity experiment?

  The gradient represents the change in temperature per unit of energy transferred.
• What happens to the temperature of water in the thermal insulation practical?

  The temperature of the water decreases over time as it loses heat.
• Why is it important to keep the surroundings temperature constant in the thermal insulation practical?

  To ensure a fair test and accurate results.
• What is the purpose of using gloves in the thermal insulation practical?

  To protect hands from burns when handling hot water.
• What is the expected outcome of the thermal insulation practical?

  The best insulator will show the least change in temperature.
• What is the relationship between energy efficiency and energy loss?

  Higher efficiency means less energy is lost as waste.
• What is the significance of the energy conservation principle in a closed system?

  It ensures that energy is neither created nor destroyed, only transformed.
• How does the specific heat capacity of oil compare to that of water?

  Oil has a lower specific heat capacity than water, requiring less energy to heat.