1.2.1 Energy Transfers and Efficiency

• Potential energy transfer occurs due to the position or state of an object.
• What happens to energy during energy transfers?

  It is transformed
• The efficiency of an energy transfer is calculated as energy output divided by energy input
• What formula is used to calculate efficiency?

  Energy output / Energy input
• Heat loss during energy transfers refers to the dissipation of energy as heat
• Light is a form of energy that can be transferred through electromagnetic waves.
• Improving efficiency is important for conserving energy and reducing waste
• Arrange the types of energy transfers from those related to motion to those related to temperature:

  1️⃣ Kinetic

  2️⃣ Potential

  3️⃣ Thermal

  4️⃣ Electrical
• Improving efficiency is important for conserving energy and reducing waste.
• A machine uses 100 Joules of energy and produces 80 Joules of useful work. Its efficiency is 80%
• Match the type of energy transfer with its description:

  Kinetic ↔️ Energy due to motion

  Potential ↔️ Energy due to position

  Thermal ↔️ Energy due to temperature difference

  Electrical ↔️ Energy through electric charge
• Give an example of kinetic energy transfer.

  A moving car
• What is the efficiency of a machine that uses 100 Joules and produces 80 Joules of useful work?

  80%
• What type of energy transfer occurs due to the motion of an object?

  Kinetic
• Electrical energy is transferred through the flow of electric charge
• What reduces the efficiency of energy transfers?

  Energy losses
• In the example above, 20% of the energy input is lost due to energy losses
• What is the effect of friction on energy efficiency?

  Reduces efficiency
• During energy transfers, different forms of energy can be transformed from one to another
• What reduces the efficiency of energy transfers?

  Energy losses
• Steps to improve energy efficiency

  1️⃣ Reduce friction

  2️⃣ Reduce heat loss

  3️⃣ Improve system design

  4️⃣ Maintain equipment
• Energy transfers refer to the movement of energy from one place or form
• Match the type of energy transfer with its description:

  Thermal ↔️ Energy transfer due to temperature difference

  Electrical ↔️ Energy transfer through electric charge flow

  Sound ↔️ Energy transfer through vibrations
• Light is a form of energy transferred through electromagnetic waves.
• What is the efficiency of a machine that uses 100 Joules of energy and produces 80 Joules of useful work?

  80%
• In a system with 80% efficiency, 20% of the energy input is lost.
• What medium is required for sound energy transfer?

  Vibrations in a medium
• Potential energy is the energy an object has due to its position
• Friction converts energy into heat, reducing efficiency.