Energy transfer Flashcards
What is the Law of Conservation of Energy?
Energy cannot be created or destroyed, only transferred from one form to another. The total energy input equals the total energy output.
Name two forms of energy involved in a moving car.
The car converts chemical energy (from fuel) into kinetic energy (movement) and some heat energy (wasted).
What energy transformation occurs in a light bulb?
Input: Electrical energy _ Output: Light energy (useful) and heat energy (wasted).
How do you calculate the efficiency of a device?
Efficiency = (Useful energy out Ö Total energy in) _ 100.
What is kinetic energy?
Kinetic energy is the energy of a moving object. The faster the object moves, the more kinetic energy it has.
How is energy wasted in most devices?
Energy is usually wasted as heat and sometimes as sound.
Name the input and output energy in a wind turbine.
Input: Kinetic energy (wind) _ Output: Electrical energy.
Explain the energy transfer in a hydroelectric power station.
Input: Gravitational potential energy (water) _ Output: Electrical energy.
What energy transformation occurs in a solar panel?
Input: Light energy _ Output: Electrical energy.
What is gravitational potential energy (GPE)?
Gravitational potential energy is the energy an object has because of its height above the ground.
How does a battery store energy?
A battery stores chemical energy, which is transformed into electrical energy when used.
Explain the energy transfer in an electric fan.
Input: Electrical energy _ Output: Kinetic energy (movement of air).
How does a car engine waste energy?
The car engine wastes energy as heat and sound.
Give an example of energy transformation in a hair dryer.
Input: Electrical energy _ Output: Heat energy and kinetic energy (moving air).
What happens to wasted energy?
Wasted energy is dissipated into the surroundings, usually as heat or sound, and becomes less useful.
What is the formula for calculating kinetic energy?
Kinetic energy = _ _ mass _ velocity_.
What is energy efficiency?
Energy efficiency is how well a device converts input energy into useful output energy.
How do you calculate the potential energy of an object?
Potential energy = mass _ gravitational field strength _ height.
Give an example of chemical energy being transformed.
Burning coal transforms chemical energy into heat and light energy.
Explain the energy transfer in a catapult.
Input: Elastic potential energy _ Output: Kinetic energy (movement of the object).
What is internal energy?
Internal energy is the energy stored in an object due to the movement of its atoms or molecules.
How can energy waste be reduced?
Energy waste can be reduced by using more efficient devices (e.g., LED bulbs) and improving insulation.
Explain the energy transformation in a television.
Input: Electrical energy _ Output: Light, sound (useful), and heat energy (wasted).
