1.4.3 Conservation of Energy

• Conservation of energy states that energy cannot be created or destroyed, but it can be transferred
• What happens to energy in a closed system according to the principle of energy conservation?

  It is transformed or transferred
• When a ball is dropped from a height, its potential energy is converted into kinetic energy as it falls.

  True
• Match the everyday example with the corresponding energy transfer or transformation:

  Bouncing ball ↔️ Potential to kinetic to thermal

  Swinging pendulum ↔️ Potential to kinetic and vice versa

  Lighting a match ↔️ Chemical to thermal and light

  Charging a battery ↔️ Electrical to chemical
• The total energy of a system remains constant during energy transformations.


  True
• Energy transformations always increase the total energy of a system.

  False
• During a pendulum's swing, potential energy is continuously converted into kinetic energy and vice versa.


  True
• When a light bulb is turned on, electrical energy is transformed into light and heat energy.

  True
• The total energy of a bouncing ball-Earth system remains constant throughout its trajectory.

  True
• In real-world mechanical systems, friction and air resistance can cause energy to dissipate as heat.


  True
• What is mechanical energy composed of?

  Potential and kinetic energy
• Kinetic energy is the energy stored due to an object's position or condition.

  False
• A closed system exchanges energy but not matter
• Order the energy transformations of a swinging pendulum from highest to lowest point:

  1️⃣ At highest point: Maximum potential energy, minimal kinetic energy

  2️⃣ As it swings down: Potential energy transforms into kinetic energy

  3️⃣ At lowest point: Minimal potential energy, maximum kinetic energy
• Match the energy concept with its definition:

  Energy Transfer ↔️ Energy moves between objects

  Energy Transformation ↔️ Energy changes from one form to another
• When a match is lit, chemical energy is transformed into thermal energy and light
• Kinetic energy can convert back into potential energy as an object rises or slows down.


  True
• In real-world mechanical systems, the total mechanical energy remains constant indefinitely.

  False
• Arrange the positions of a pendulum from highest to lowest energy:

  1️⃣ Highest point with maximum potential energy

  2️⃣ Lowest point with maximum kinetic energy
• Open systems exchange both matter and energy
• In electrical systems, energy is always created rather than transformed.

  False
• The total energy in an electrical system decreases over time due to friction.

  False
• What happens to potential energy when steam condenses back into liquid water?

  It is released as heat
• Efficiency is calculated as (Useful Energy Output) / (Total Energy Input) multiplied by 100
• Match the energy state of a swinging pendulum with its corresponding energy form:

  At highest point ↔️ Maximum potential energy

  At lowest point ↔️ Maximum kinetic energy
• When a light bulb is turned on, electrical energy is transformed into light and heat
• What are the two key principles related to the conservation of energy?

  Energy transfer and transformation
• When charging a battery, electrical energy is converted into chemical potential energy.


  True
• What does the principle of conservation of energy state?

  Energy cannot be created or destroyed
• What happens to the total energy in a closed system according to the conservation of energy?

  It remains constant
• What does the principle of energy conservation state about energy creation or destruction?

  Energy cannot be created or destroyed
• What is the definition of energy transfer?

  Energy moves between objects
• What type of energy is stored in a bouncing ball at the top of its trajectory?

  Potential energy
• What are the two types of mechanical energy?

  Potential and kinetic
• Potential energy converts into kinetic energy when an object moves from a higher position to a lower one.


  True
• Match the system with its energy transformations:

  Bouncing Ball ↔️ Highest position to impact

  Roller Coaster ↔️ Top of the first hill to downward slopes

  Pendulum ↔️ At highest points
• When an object moves from a higher position to a lower position, its potential energy is transformed into kinetic
• Match the system type with its exchange with surroundings:

  Open System ↔️ Exchanges both matter and energy

  Closed System ↔️ Exchanges energy but not matter
• Conservation of energy applies only to open systems.

  False
• What does the conservation of energy in mechanical systems state?

  Total mechanical energy remains constant