1.
Which kind of energy is associated with the motion, position, or shape of an object?
Correct Answer
C. Mechanical
Explanation
Mechanical energy is associated with the motion, position, or shape of an object. This type of energy is possessed by objects in motion or at rest, as well as by objects that have the potential to move or change shape. It includes both kinetic energy (energy of motion) and potential energy (energy stored in an object due to its position or shape).
2.
An object's mechanical energy is a combination of its ___ and ___.
Correct Answer
A. Kinetic energy and potential energy
Explanation
An object's mechanical energy is a combination of its kinetic energy and potential energy. Kinetic energy is the energy an object possesses due to its motion, while potential energy is the energy an object possesses due to its position or condition. The sum of these two forms of energy gives the object its total mechanical energy.
3.
A basketball has its greatest potential energy when it
Correct Answer
C. Reaches its highest point
Explanation
When a basketball reaches its highest point, it has the maximum potential energy. At this point, the basketball has gained the most amount of gravitational potential energy due to its elevation. As it falls back down, this potential energy will be converted into kinetic energy. Therefore, the basketball has its greatest potential energy when it reaches its highest point.
4.
How does a ball's energy change as it falls to the ground?
Correct Answer
A. It's potential energy changes to kinetic energy.
Explanation
As the ball falls to the ground, its potential energy decreases because it is moving closer to the Earth's surface. At the same time, its kinetic energy increases because it is gaining speed due to the force of gravity. Therefore, the ball's potential energy is converted into kinetic energy as it falls.
5.
PE = 10 JKE = 5 JME = ?
Correct Answer
B. 15 J
Explanation
The given equation states that the potential energy (PE) is equal to 10 J and the kinetic energy (KE) is equal to 5 J. The question asks for the missing value of mechanical energy (ME). Mechanical energy is the sum of potential energy and kinetic energy, so to find ME, we need to add PE and KE together. Therefore, the missing value of ME is 15 J.
6.
ME = 10 J
PE = 2 J
KE = ?
Correct Answer
A. 8 J
Explanation
The total mechanical energy (ME) of a system is the sum of its potential energy (PE) and kinetic energy (KE). In this case, the given PE is 2 J. Since the question asks for the value of KE, we need to subtract the PE from the ME. Therefore, the KE would be 10 J - 2 J = 8 J.
7.
KE and PE are types of ME.
Correct Answer
A. True
Explanation
The statement is true because KE (kinetic energy) and PE (potential energy) are both types of mechanical energy (ME). KE is the energy possessed by an object in motion, while PE is the energy that an object possesses due to its position or condition. Therefore, both KE and PE fall under the category of ME.
8.
Which of the following is NOT a form of energy?
Correct Answer
A. Caribbean
9.
What do we call the central area of an atom that contains the protons and neutrons?
Correct Answer
B. Nucleus
Explanation
The nucleus is the central area of an atom that contains the protons and neutrons. It is the densest part of the atom and carries a positive charge due to the presence of protons. The nucleus is surrounded by a cloud of electrons, which orbit around it in specific energy levels. The protons and neutrons in the nucleus determine the atomic mass and are responsible for the stability of the atom.
10.
When two atomic nuclei join together and release energy, it is called
Correct Answer
D. Fusion
Explanation
When two atomic nuclei join together and release energy, it is called fusion. Fusion is the process in which two atomic nuclei combine to form a heavier nucleus, releasing a large amount of energy in the process. This is the process that powers the sun and other stars, where hydrogen nuclei combine to form helium. Fusion is different from fission, which is the process of splitting an atomic nucleus into smaller parts. Supernova and catastrophe are unrelated to the process of atomic nuclei joining together and releasing energy.
11.
When an atomic nucleus splits apart and gives off energy it is called
Correct Answer
A. Fission
Explanation
The process described in the question, where an atomic nucleus splits apart and releases energy, is known as fission. Fission is a nuclear reaction that occurs in heavy elements such as uranium or plutonium, where the nucleus is split into two smaller nuclei, releasing a large amount of energy in the process. This process is commonly used in nuclear power plants and atomic bombs. Fusion, on the other hand, is the process of combining two atomic nuclei to form a heavier nucleus, and it also releases a significant amount of energy. However, the question specifically mentions the splitting apart of the nucleus, which aligns with the concept of fission.
12.
Where does nuclear fusion happen?
Correct Answer
B. In the sun
Explanation
Nuclear fusion occurs in the sun. The sun's core is extremely hot and dense, creating the perfect conditions for hydrogen atoms to collide and fuse together, forming helium. This fusion process releases a tremendous amount of energy in the form of light and heat, which is what powers the sun and provides heat and light to the Earth. Nuclear reactors on Earth also use nuclear fusion, but they are not as efficient or sustainable as the sun's fusion process.
13.
Where does nuclear fission happen?
Correct Answer
D. In a nuclear reactor
Explanation
Nuclear fission is a process that involves the splitting of atomic nuclei, releasing a large amount of energy. This process occurs in a controlled environment called a nuclear reactor. In a nuclear reactor, the fission of uranium or plutonium atoms is induced by bombarding them with neutrons, which leads to a chain reaction. This reaction generates heat, which is then used to produce steam and drive turbines, ultimately generating electricity. Therefore, the correct answer is "in a nuclear reactor."
14.
A pencil is a solid so it's particles don't move.
Correct Answer
B. False
Explanation
This statement is false because a pencil is not a solid in the sense that its particles do not move. In reality, the particles in a pencil, like any other object, are constantly in motion due to thermal energy. Therefore, the statement is incorrect.
15.
The more thermal energy an object has, the higher its temperature.
Correct Answer
A. True
Explanation
When an object has more thermal energy, it means that its molecules are vibrating at a higher rate. This increased molecular motion results in a higher temperature. Temperature is a measure of the average kinetic energy of the particles in an object, so when an object has more thermal energy, it has a higher temperature. Therefore, the statement that the more thermal energy an object has, the higher its temperature, is true.
16.
What kind of energy does a battery produce?
Correct Answer
C. Electrical
Explanation
A battery produces electrical energy. When a battery is connected to a circuit, a chemical reaction occurs inside the battery, causing a buildup of electrons at the negative terminal and a deficit of electrons at the positive terminal. This creates a potential difference, or voltage, between the terminals. When a circuit is completed by connecting a load, such as a light bulb, to the battery, the excess electrons flow from the negative terminal through the circuit to the positive terminal, creating an electric current and producing electrical energy.
17.
Electromagnetic energy must travel through a medium like air or water or a wall.
Correct Answer
B. False
Explanation
Electromagnetic energy does not require a medium to travel through. Unlike mechanical waves, such as sound waves, which need a medium to propagate, electromagnetic waves can travel through a vacuum, like outer space, as they are self-propagating disturbances of electric and magnetic fields. Therefore, the statement that electromagnetic energy must travel through a medium like air, water, or a wall is false.
18.
Which of the following is NOT an example of electromagnetic energy?
Correct Answer
B. Electricity
Explanation
Electricity is not an example of electromagnetic energy because it is the flow of electrons through a conductor, whereas electromagnetic energy refers to the energy carried by electromagnetic waves such as radio waves, microwaves, and light. While electricity is often generated using electromagnetic principles, it is not itself a form of electromagnetic energy.
19.
Why do we need to eat food?
Correct Answer
D. When we break down food we get the energy in the chemical bonds in its atoms.
Explanation
Our bodies need energy to carry out various functions such as breathing, moving, and even thinking. This energy is obtained by breaking down the food we eat. Food contains chemical bonds that store energy. When we digest and metabolize food, these bonds are broken, releasing energy that our bodies can use. Therefore, the statement "When we break down food we get the energy in the chemical bonds in its atoms" accurately explains why we need to eat food.
20.
A change from one form of energy to another is called
Correct Answer
A. A transformation
Explanation
A change from one form of energy to another is referred to as a transformation. This term is commonly used to describe the process of converting energy from one type to another, such as the transformation of electrical energy into light energy in a light bulb or the transformation of chemical energy into mechanical energy in a car engine. The other options, transfer, transmission, and transition, do not accurately describe the process of changing energy from one form to another.
21.
A hair straightener makes the following energy transformation:
Correct Answer
B. Electrical energy > thermal energy > kinetic energy
Explanation
A hair straightener converts electrical energy into thermal energy, which is then used to heat up the plates of the straightener. This thermal energy is then transferred to the hair, causing the hair to straighten. The kinetic energy is the final result of the hair straightener's energy transformation, as it is the energy that allows the straightener to move and exert force on the hair.
22.
What are the transformations involved in a flashlight?
Correct Answer
A. chemical > electrical > light
Explanation
A flashlight involves the transformation of chemical energy into electrical energy, and then the electrical energy is transformed into light energy. The chemical reaction inside the flashlight's battery produces electrical energy, which powers the light bulb or LED, converting the electrical energy into light energy.
23.
Why does a pendulum eventual stop moving?
Correct Answer
D. Friction causes the energy to be converted to thermal energy.
Explanation
The correct answer is that friction causes the energy to be converted to thermal energy. When a pendulum swings, it experiences air resistance and friction at the pivot point. This friction gradually slows down the pendulum's motion, converting its kinetic energy into thermal energy. As the pendulum loses energy, it eventually comes to a stop.
24.
What is the law of conservation of energy?
Correct Answer
D. Energy cannot be created or destroyed.
Explanation
The law of conservation of energy states that energy cannot be created or destroyed, but it can only be transferred or transformed from one form to another. This principle is based on the understanding that the total amount of energy in a closed system remains constant over time. Therefore, energy can neither be created nor destroyed, only converted from one form to another. This concept is fundamental in understanding the behavior and interactions of energy in various systems.