# (I) Explain the term energy transformation.

(II) Describe the energy transformation occurring in a swinging simple pendulum. Justify each transformation along the path of swing.

(III) A person needs a power supply of 3.5kW for a normal lifestyle. What area of solar collector would be needed to produce this energy.Assume 6% efficiency.

## (I) Energy transformation refers to the process by which energy changes from one form to another. It occurs when energy is converted from one type, such as chemical, thermal, electrical, or mechanical, to another form.

(II) In a swinging simple pendulum, there are several energy transformations along the path of the swing. Initially, when the pendulum is at its highest point, it has the highest potential energy. As it begins to swing downwards, this potential energy is converted into kinetic energy, which is the energy of motion.

As the pendulum reaches its lowest point, the kinetic energy is at its maximum, and the potential energy is at its minimum. As the pendulum starts moving back up, the kinetic energy is converted back into potential energy. This conversion continues until the pendulum reaches its highest point again.

Throughout the swing, there are also some minor energy losses due to air resistance and friction, which convert some of the energy into heat. However, these losses are usually small and can be ignored in most cases.

(III) To determine the area of the solar collector needed to produce 3.5 kW of power, we need to consider the efficiency of the solar collector. Assuming a 6% efficiency, we can calculate the total energy needed by dividing the power by the efficiency:

Power needed = 3.5 kW / 0.06 = 58.33 kW

Solar collectors, also known as photovoltaic panels, typically have a power output rating in watts per square meter, ranging from 100-400 W/m².

To find the area of the solar collector needed, we can divide the power needed by the power output per square meter:

Area needed = Power needed / Power output per square meter

Assuming a power output of 200 W/m²:

Area needed = 58.33 kW / 0.2 kW/m² = 291.65 m²

Therefore, approximately 291.65 square meters of solar collector surface area would be needed to produce 3.5 kW of power with a 6% efficiency.

## (I) Energy transformation refers to the process by which energy changes from one form to another. Energy can neither be created nor destroyed, but it can be converted from one type to another. This principle is known as the law of conservation of energy. The different forms of energy include mechanical, thermal, chemical, electrical, nuclear, and electromagnetic energy.

(II) In a swinging simple pendulum, the energy transformation occurs as follows:

1. Potential Energy to Kinetic Energy: When the pendulum is at its highest point, it possesses potential energy due to its height above the equilibrium position. As it starts swinging downward, this potential energy is converted into kinetic energy, which is the energy of motion.

2. Kinetic Energy to Potential Energy: As the pendulum swings downward, its speed increases, and the kinetic energy reaches its maximum at the lowest point. As the pendulum swings upward, the kinetic energy is gradually converted back into potential energy. At the highest point, the pendulum again possesses maximum potential energy.

3. Negligible energy losses: During the swings, there may be some small energy losses due to air resistance and friction in the pendulum's pivot point. However, these losses are usually negligible and can be ignored for most practical purposes.

The energy transformation in a swinging simple pendulum is a continuous interchange between potential and kinetic energy throughout its oscillation.

(III) To calculate the area of the solar collector required to produce 3.5 kW of power with a 6% efficiency, we can use the following steps:

Step 1: Convert kilowatts to watts:

3.5 kW = 3,500 watts

Step 2: Account for efficiency:

Since the solar collector has an efficiency of 6%, we need to divide the required power by the efficiency:

3,500 watts / 0.06 = 58,333.33 watts

Step 3: Calculate the area of the solar collector:

The area of the solar collector required is dependent on the available solar irradiance, which varies depending on geographical location and orientation. However, we can estimate the area by assuming a solar irradiance of 1,000 watts/m².

Area = Power / (Solar Irradiance × Efficiency)

Area = 58,333.33 watts / (1,000 watts/m² × 0.06 efficiency)

Area ≈ 972.22 m²

Therefore, approximately 972.22 square meters of solar collector area would be needed to produce 3.5 kW of power with a 6% efficiency.

## (I) Energy transformation refers to the conversion of one form of energy into another form. Energy can exist in several forms such as mechanical, thermal, chemical, electromagnetic, and nuclear. When energy undergoes transformation, it changes from one form to another, while the total amount of energy remains constant according to the law of conservation of energy.

(II) In a swinging simple pendulum, the energy transformation can be observed as follows:

1. Potential Energy to Kinetic Energy: As the pendulum is lifted to one side, potential energy is stored in the system. This potential energy is directly proportional to the height to which the mass is lifted. As the pendulum is released, the potential energy is gradually converted into kinetic energy, which is associated with the motion of the pendulum.

2. Kinetic Energy to Potential Energy: As the pendulum reaches its highest point on the opposite side, its kinetic energy is at its minimum, while the potential energy is at its maximum. This conversion occurs as the swinging motion slows down, and the kinetic energy is transferred back to potential energy.

3. Kinetic Energy to Thermal Energy: During the swing, some of the mechanical energy is converted into thermal energy due to air resistance and friction at the pivot point. This results in a slight decrease in the total mechanical energy of the system.

(III) To calculate the area of the solar collector required to produce a power supply of 3.5 kW (kilowatts) with a 6% efficiency, we can follow these steps:

1. Convert the power supply from kilowatts to watts: 3.5 kW = 3,500 watts.

2. Apply the efficiency factor: Since the efficiency of 6% means that only 6% of the solar energy will be converted into usable electrical energy, we need to account for this. Divide the power supply by the efficiency as a decimal: 3,500 watts / 0.06 = 58,333.33 watts.

3. Calculate the energy received from the sun: The total solar energy received on Earth's surface is about 1,000 watts per square meter (W/m2) on average. So, divide the energy produced by the solar collector by the solar energy available per square meter: 58,333.33 watts / 1,000 W/m2 = 58.33333 m2.

Therefore, approximately 58.33 square meters of solar collector area would be needed to produce a power supply of 3.5 kW with a 6% efficiency.