Which of the following is an example of an energy transformation?
Explanation: The correct answer is A) Burning wood to produce heat. Burning wood is an example of a chemical energy transformation into heat energy. Chemical energy stored in wood is converted to heat energy during the combustion process.
Which of the following statements is true regarding energy transformations?
Explanation: The correct answer is C) Energy is conserved during transformations. Energy transformations involve the conversion of energy from one form to another, but the total amount of energy remains constant. This principle is known as the conservation of energy.
What is the efficiency of an energy transformation that converts 400 J of input energy into 320 J of useful output energy?
Explanation: The correct answer is C) 80%. Efficiency is calculated by dividing the useful output energy by the input energy and multiplying by 100%. In this case, (320 J / 400 J) * 100% = 80%.
Which of the following factors can reduce the efficiency of an energy transformation?
Explanation: The correct answer is D) All of the above. Factors such as friction, heat loss, and incomplete combustion can reduce the efficiency of an energy transformation. These factors result in the dissipation of energy in forms that are not useful for the intended purpose.
Which of the following energy transformations is an example of an inefficient process?
Explanation: The correct answer is A) Electric energy to light energy in an incandescent bulb. Incandescent bulbs are inefficient because they convert a significant portion of the electrical energy into heat energy rather than light energy. This results in wasted energy and lower overall efficiency.