SCI8 Energy Transformations & Law of Conservation

When a windmill turns the energy from the wind into electricity, what type of energy transformation is happening?

• Wind energy to electrical energy

• Solar energy to thermal energy

• Kinetic energy to sound energy

• Chemical energy to light energy

Answer explanation

In this question, we are asked about the energy transformation that occurs when a windmill turns wind into electricity. The correct answer is 'Wind energy to electrical energy' because windmills harness the kinetic energy from the wind and convert it into electrical energy through the usage of a turbine and generator. The other options are not relevant to the energy transformation happening in a windmill.

When you eat a banana, which type of energy transformation occurs as your body converts the food into energy?

• Thermal energy to kinetic energy

• Chemical energy to thermal energy

• Gravitational energy to sound energy

• Electrical energy to magnetic energy

Answer explanation

When you eat a banana, your body undergoes a process of energy transformation. The energy stored in the banana's chemical bonds is converted into thermal energy, which your body uses for various functions. This transformation is known as chemical energy to thermal energy conversion and is essential for sustaining life.

What happens to the total amount of energy when you ride a bike downhill and your potential energy is converted into kinetic energy?

• It decreases

• It increases

• It remains constant

• It disappears

Answer explanation

The total amount of energy is conserved according to the law of conservation of energy. This law dictates that energy cannot be created or destroyed, but only transferred or transformed. Therefore, when you ride a bike downhill, your potential energy is converted into kinetic energy, not disappearing or reducing but remaining constant.

When you strike a match to light a candle, what type of energy transformation occurs?

• Gravitational energy to thermal energy

• Electrical energy to sound energy

• Chemical energy to thermal energy

• Solar energy to kinetic energy

Answer explanation

When you strike a match to light a candle, it's a chemical reaction taking place. This chemical reaction, known as combustion, transforms stored chemical energy into thermal (or heat) energy. This is why the correct answer is 'Chemical energy to thermal energy'.

When a car engine burns fuel to move the vehicle, what energy transformation is taking place?

• Electrical energy to thermal energy

• Chemical energy to kinetic energy

• Solar energy to sound energy

• Wind energy to potential energy

Answer explanation

In a car engine, fuel is burned to move the vehicle. This process involves the transformation of energy from one form to another. Specifically, the chemical energy stored in the fuel is converted into kinetic energy, which powers the car's motion. This energy transformation aligns with the correct choice: chemical energy to kinetic energy.

What kind of energy transformation occurs when a television converts electrical energy into sound and light energy?

• Chemical energy to thermal energy

• Nuclear energy to electrical energy

• Electrical energy to magnetic energy

• Elastic energy to kinetic energy

Answer explanation

The energy transformation that occurs when a television converts electrical energy into sound and light energy is Electrical energy to magnetic energy. Televisions use electrical energy to generate images and sound, which involve electromagnetic waves (i.e., light waves and sound waves). Therefore, the correct transformation is from electrical energy to magnetic energy.

When you jump on a trampoline, what type of energy transformation happens as you bounce up and down?

• Elastic energy to gravitational potential energy

• Light energy to sound energy

• Magnetic energy to nuclear energy

• Wind energy to electrical energy

Answer explanation

When you jump on a trampoline, the springs stretch and accumulate elastic energy. When you bounce upwards, the springs contract, converting this elastic energy into gravitational potential energy. This is why the correct answer is 'Elastic energy to gravitational potential energy'.

What law states that energy cannot be created or destroyed, only transformed from one form to another?

• Newton's Third Law of Motion

• The Law of Gravity

• The Law of Conservation of Energy

• The Law of Reflection

Answer explanation

The Law of Conservation of Energy is the correct choice. This law states that energy cannot be created or destroyed, only transformed from one form to another. The other options, Newton's Third Law of Motion, The Law of Gravity, and The Law of Reflection, do not address the concept of energy transformation.

When a torch (flashlight) is turned on, what energy transformation occurs as it produces light from electrical energy?

• Sound energy to thermal energy

• Electrical energy to light energy

• Chemical energy to kinetic energy

• Solar energy to nuclear energy

Answer explanation

When a torch (flashlight) is turned on, the energy transformation that occurs is electrical energy being converted into light energy. The torch's battery provides electrical energy, which is then transformed into light energy by the bulb, emitting visible light. The other options do not accurately describe the energy transformation taking place in a torch.

When you switch on an electric fan, what type of energy transformation takes place as electricity is converted into kinetic energy of the fan blades?

• Thermal energy to electrical energy

• Gravitational energy to chemical energy

• Electrical energy to kinetic energy

• Nuclear energy to sound energy

Answer explanation

The question asks about the energy transformation that occurs when an electric fan is switched on. The correct answer is 'Electrical energy to kinetic energy' because, during this process, the electrical energy provided to the fan motor is converted into the kinetic energy of the spinning fan blades.