You are cooking pasta and putting a pot of water on an electric stove. When the water starts to boil, you add the pasta. What energy transformation occurs to cook the pasta?
a
heat energy to mechanical energy
b
nuclear energy to heat energy
c
electric energy to heat energy
d
mechanical energy to light energy
You are cooking pasta and putting a pot of water on an electric stove. When the water starts to boil, you add the pasta. What energy transformation occurs to cook the pasta?
a
heat energy to mechanical energy
b
nuclear energy to heat energy
c
electric energy to heat energy
d
mechanical energy to light energy
The correct answer is c) electric energy to heat energy. When the pot of water is placed on the electric stove, the electric energy from the stove is transformed into heat energy, which causes the water to heat up and eventually reach boiling point.
Hydroelectric dams work by blocking the path of a water source to create an area with water held back by the dam. The dam can then be opened to allow water to be released. The energy from the moving water is used and transformed into electrical energy. What type of energy does a hydroelectric dam capture as the water passes through?
a
Mechanical Energy
b
Light Energy
c
Sound Energy
d
Nuclear Energy
The correct answer is a) Mechanical energy. As the water passes through the hydroelectric dam, its kinetic energy (due to its movement) is converted into mechanical energy. This mechanical energy is then used to drive turbines, which in turn generate electrical energy.
The picture shows solar panels that power all appliances in this house.CRp0Mm8Ia-8XKLXKgFQVbDPIc6vtyPBid3gdRspXuEgncvMHMofQAo9RWNcOMtuhWkSK21HzjcZz1K6sQZemR2Yii7IZKhKPYJhMcNMXTOkgoZ8AMZrLPz9TL4-Riq9FQUPWkxidgTz87OVcUhwx3p0
An oven is being used to bake cookies in this house. What energy transformations occur when baking cookies in this house?
a
heat energy → light energy → chemical energy
b
light energy → electrical energy → heat energy
c
heat energy → chemical energy → light energy
d
heat energy → electrical energy → chemical energy
The correct answer is a) heat energy → light energy → chemical energy.
When baking cookies in an oven powered by solar panels, the energy transformations occur as follows:
1. Heat energy: The electrical energy from the solar panels is transformed into heat energy, which is used to heat the oven and baking chamber.
2. Light energy: The heat energy inside the oven is then transformed into light energy as the heating elements glow and emit light.
3. Chemical energy: Finally, the light energy is transformed into chemical energy as the cookies undergo a chemical reaction and bake, leading to the formation of delicious cookies.
The total amount of energy in the universe never changes, but the availability of each different type of energy to do work can change tremendously. What best explains this change in available energy?
a
Energy can only be created through nuclear reactions.
b
Energy is always converted with 100 percent efficiency.
c
Energy can only be transferred as heat.
d
Energy is regularly changing from one form into another.
The correct answer is d) Energy is regularly changing from one form into another.
The total amount of energy in the universe is constant, according to the law of conservation of energy. However, energy can change from one form to another. For example, potential energy can be converted into kinetic energy, or mechanical energy can be converted into heat energy.
The availability of each different type of energy to do work can change tremendously because energy is constantly being transformed between different forms. Some forms of energy may be more readily available to do work in a given situation, while others may be less accessible or not useful for performing work.
An aluminum block with a temperature of 300oC is placed into 200 milliliters of water with a temperature of 20oC. Which statement best describes what will be observed in this experiment?
a
Heat will flow from the metal to the water until both are at a temperature somewhere between 20oC and 300oC.
b
Heat will flow from the metal to the water until both are 20oC.
c
Heat will flow from the metal to the water until both are 300oC.
d
Heat will flow from the metal to the water until both are at the temperature of the container.
The correct answer is a) Heat will flow from the metal to the water until both are at a temperature somewhere between 20oC and 300oC.
In this experiment, heat will flow from the aluminum block to the water, as heat tends to move from higher temperature regions to lower temperature regions. The heat transfer will continue until both the aluminum block and the water reach an equilibrium temperature somewhere between the initial temperatures of 20oC and 300oC. The specific equilibrium temperature will depend on the respective thermal properties of the aluminum block and the water.