Energy

• What is the principle regarding energy in physics?

  Energy is never created or destroyed.
• What does the principle of energy transfer imply?

  Energy is transferred between different forms and objects.
• What are the different forms of energy?

  • Thermal or internal energy
  • Kinetic energy
  • Gravitational potential energy
  • Elastic potential energy
  • Chemical energy
  • Magnetic energy
  • Electrostatic energy
  • Nuclear energy
• What is thermal energy related to?

  It is related to the temperature of an object.
• What is kinetic energy associated with?

  It is associated with the movement of an object.
• What does gravitational potential energy depend on?

  It depends on an object's position in a gravitational field.
• What is elastic potential energy?

  Energy held in an already stretched spring.
• What is chemical energy?

  Energy held in chemical bonds.
• What is magnetic energy?

  Energy that holds magnets to your fridge.
• What is electrostatic energy?

  Energy that gives you a shock when touching metal.
• What is nuclear energy?

  Energy obtained from breaking atoms apart.
• How can energy be transferred between stores?

  Through mechanical, electrical, heating, or radiation methods.
• What is a system in physics?

  A collection of matter being studied.
• What happens in an open system?

  It can exchange energy with the outside world.
• What is a closed system?

  It is separate from the outside world.
• What is the overall energy change in a closed system?

  The overall change is always zero.
• How does energy transfer occur in a kettle?

  1. Electrical energy flows to the heating element.
  2. It is transferred to the thermal energy store of the kettle.
  3. The heating element warms the water's thermal energy store.
• What does "work done" mean in terms of energy transfer?

  It refers to energy transferred during a process.
• What is mechanical work done?

  Using a force to move an object.
• What is electrical work done?

  Energy required to overcome resistance in wires.
• How does friction do work on a train?

  It slows the train by transferring energy to heat.
• What are the two main types of work done in energy transfer?

  • Mechanical work done
  • Electrical work done
• What is kinetic energy?

  Energy possessed due to motion
• What two factors determine kinetic energy?

  Speed and mass of the object
• How does speed affect kinetic energy?

  Faster objects have more kinetic energy
• How does mass affect kinetic energy when speed is constant?

  More mass means more kinetic energy
• If a plane weighs 20 tons and a particle weighs 0.1 grams, which has more kinetic energy at the same speed?

  The plane has more kinetic energy
• What happens to kinetic energy if a plane travels at 5 m/s and a particle at 4000 m/s?

  We must calculate using the kinetic energy equation
• What is the equation for kinetic energy?

  $E_k =$$\frac{1}{2} m v^2$
• What does each symbol in the kinetic energy equation represent?

  E is energy, m is mass, v is velocity
• How do you convert 20 tons to kilograms?

  20 tons equals 20,000 kilograms
• How do you convert 0.1 grams to kilograms?

  0.1 grams equals 0.0001 kilograms
• What is the kinetic energy of the plane traveling at 5 m/s?

  250,000 joules or 250 kilojoules
• What is the kinetic energy of the particle traveling at 4000 m/s?

  800 joules or 0.8 kilojoules
• Why did the particle have less kinetic energy despite its higher speed?

  Its mass was significantly lower
• What are the key points about kinetic energy calculation?

  • Kinetic energy depends on speed and mass
  • Use the equation: $E_k =$$\frac{1}{2} m v^2$
  • Convert units to kilograms and meters per second
  • Calculate separately for different objects
• What factors influence kinetic energy in moving objects?

  • Speed: Faster objects have more energy
  • Mass: Heavier objects have more energy at the same speed
  • Both factors must be considered in calculations