1.
All Energy adheres to the Law of Conervation of Energy. Why is a light bulb not 100% efficient?
Correct Answer
B. All energy transfers lose energy in the form of heat
2.
What is the potential energy of a 80 kg tourist at the top of a building that is 400 m high?
Correct Answer
D. 313600 J
Explanation
The potential energy of an object is given by the formula PE = mgh, where m is the mass of the object, g is the acceleration due to gravity, and h is the height. In this case, the mass of the tourist is 80 kg, the height of the building is 400 m, and the acceleration due to gravity is approximately 9.8 m/s^2. Plugging these values into the formula, we get PE = (80 kg)(9.8 m/s^2)(400 m) = 313600 J.
3.
Energy produced by the sun is
Correct Answer
A. Nuclear
Explanation
The sun produces energy through nuclear reactions, specifically nuclear fusion. In the sun's core, hydrogen atoms combine to form helium, releasing a tremendous amount of energy in the process. This energy is then radiated outwards as sunlight and other forms of electromagnetic radiation. Therefore, the correct answer is nuclear.
4.
If the velocity of an object is 1m/s, then increases to 2 m/s, what will happen to the kinetic energy of the object?
Correct Answer
D. It will be multiplied by 4
Explanation
When the velocity of an object increases from 1 m/s to 2 m/s, the kinetic energy of the object is directly proportional to the square of its velocity. Therefore, when the velocity is doubled, the kinetic energy will be multiplied by 4 (2^2), resulting in an increase in kinetic energy.
5.
Energy is measured in
Correct Answer
C. Joules
Explanation
Energy is a physical quantity that is measured in joules. Joules are the standard unit of measurement for energy in the International System of Units (SI). Newtons are a unit of force, amps are a unit of electric current, and kilograms are a unit of mass. None of these units are appropriate for measuring energy. Therefore, the correct answer is joules.
6.
Ultraviolet light is an example of
Correct Answer
B. Electromagnetic energy
Explanation
Ultraviolet light is a form of electromagnetic energy. Electromagnetic energy consists of waves that vary in frequency and wavelength, and ultraviolet light falls within this spectrum. It is characterized by its high energy and shorter wavelength compared to visible light. Ultraviolet light is commonly associated with the sun's rays and is responsible for causing sunburns and tanning.
7.
A magic turtle has a mass of 47kg and can run 31 m/s. What is his kinetic energy?
Correct Answer
A. 22583.5 J
Explanation
The kinetic energy of an object is given by the formula KE = 0.5 * mass * velocity^2. In this case, the mass of the magic turtle is given as 47kg and the velocity is given as 31 m/s. Plugging these values into the formula, we get KE = 0.5 * 47 * (31^2) = 22583.5 J. Therefore, the correct answer is 22583.5 J.
8.
Pedaling a bike is an example of
Correct Answer
C. Mechanical energy
Explanation
Pedaling a bike involves the conversion of human energy into the mechanical energy required to move the bike. Mechanical energy refers to the energy associated with the motion and position of objects. When a person pedals a bike, they apply force to the pedals, which causes the bike to move. This movement is a form of mechanical energy, as it involves the transfer of energy from the person's muscles to the bike's wheels. Therefore, pedaling a bike is an example of mechanical energy.
9.
When you drag your book across a table, friction will convert
Correct Answer
B. Kinetic energy to thermal energy
Explanation
When you drag your book across a table, friction between the book and the table surface will cause the book to slow down. This decrease in kinetic energy is converted into thermal energy, as the friction generates heat. Therefore, the correct answer is "kinetic energy to thermal energy."
10.
In the energy transfer diagram of a battery and a light bulb,
Correct Answer
D. Electrical energy is transferred to light (electromagnetic) energy
Explanation
The correct answer is electrical energy is transferred to light (electromagnetic) energy. This is because a battery provides electrical energy, which is then transferred to the light bulb. Inside the light bulb, electrical energy is converted into light energy, which is a form of electromagnetic energy.
11.
Point A represents matter at a solid. What phase change is happening at point B?
Correct Answer
A. Freezing
Explanation
At point A, matter is represented as a solid, which means it is in a state where its particles are tightly packed and have a fixed shape and volume. Moving to point B, the phase change happening is freezing. Freezing occurs when a substance changes from a liquid to a solid state, resulting in particles becoming more closely packed and forming a fixed shape. Therefore, the correct answer is freezing.
12.
Point C represents the melting point of a substance. What would Point E represent?
Correct Answer
D. Vaporization
Explanation
Point E represents vaporization because it is the process by which a substance changes from a liquid to a gas. The melting point, represented by Point C, is the temperature at which a substance changes from a solid to a liquid. Therefore, Point E, which is located after Point C, would represent the next phase transition in which the substance changes from a liquid to a gas.
13.
Which one of the following is a conductor?
Correct Answer
B. Metal
Explanation
Metal is a conductor because it allows the flow of electric current through it. Unlike insulators, such as straw and wool, which impede the flow of electricity, metals have free electrons that can move easily, facilitating the transfer of electric charge. Therefore, metal is the correct answer.
14.
A charged balloon can pick up small bits of paper, proving that its ____ force is stronger than Earth's gravitational force.
Correct Answer
C. Electrical force
Explanation
When a balloon is charged, it gains an excess of electrons. These excess electrons create an electric field around the balloon. The electric field exerts a force on the small bits of paper, causing them to be attracted to the balloon. This demonstrates that the electrical force, generated by the excess charge on the balloon, is stronger than the gravitational force exerted by the Earth on the paper.
15.
The phase of matter with a definite chape and volume is
Correct Answer
D. Solid
Explanation
A solid is the phase of matter that has a definite shape and volume. Unlike liquids and gases, solids do not flow and maintain their shape and volume under normal conditions. The particles in a solid are closely packed together and have strong intermolecular forces that hold them in place. This arrangement allows solids to maintain their shape and volume, making them distinct from other phases of matter.
16.
The phase with the most energetic molecules is
Correct Answer
C. Gas
Explanation
Gas molecules have the highest energy compared to molecules in other phases. In the gas phase, molecules are not bound together and are free to move around rapidly and collide with each other. This constant motion and collision result in higher kinetic energy, making gas molecules more energetic than those in the solid or liquid phases. Absolute zero, on the other hand, refers to the lowest possible temperature where all molecular motion ceases, so it does not represent a phase with energetic molecules.
17.
When submimation occurs,
Correct Answer
A. Solid is converted to gas
Explanation
When sublimation occurs, solid is converted directly into gas without going through the liquid phase. This process happens when the temperature and pressure conditions are such that the solid particles gain enough energy to break their intermolecular bonds and escape into the gas phase. This is exemplified by substances like dry ice (solid carbon dioxide) which sublimes at room temperature, going from a solid state directly to a gaseous state.
18.
Ohms () is the unit of measurement for
Correct Answer
B. Resistance
Explanation
The unit of measurement for resistance is Ohms. Resistance is a property of a material that hinders the flow of electric current. It is measured in Ohms, symbolized by the Greek letter omega (Ω). Resistance is important in determining the amount of current that can flow through a circuit and is used in various electrical calculations and circuit designs.
19.
Like charges
Correct Answer
B. Repel
Explanation
Like charges repel each other because they have the same charge. According to the principle of electrostatics, like charges create an electric field that pushes them away from each other. This is due to the fact that like charges have a mutual force of repulsion, causing them to move apart and maintain a certain distance between them.
20.
Which temperature scale does water have a boiling point of 100 and a freezing point of 0
Correct Answer
B. Celsius
Explanation
Water has a boiling point of 100 degrees Celsius and a freezing point of 0 degrees Celsius. This means that the Celsius temperature scale is the correct answer. Fahrenheit has a boiling point of 212 degrees and a freezing point of 32 degrees, Kelvin has a boiling point of 373.15 degrees and a freezing point of 273.15 degrees, and Rankine has a boiling point of 671.67 degrees and a freezing point of 491.67 degrees.
21.
Tension breaker: Pizza is
Correct Answer
A. Delicious
Explanation
The given correct answer "delicious" suggests that pizza is enjoyable and flavorful. It implies that the taste of pizza is highly satisfying and appealing to most people. This answer indicates that the person who chose it finds pizza to be a delicious food option.
22.
The way in which energy travels the length of a metal is
Correct Answer
C. Conduction
Explanation
Conduction is the correct answer because it refers to the process of energy transfer through direct contact between particles in a substance, such as metal. In conduction, energy is transferred from higher energy particles to lower energy particles, causing them to vibrate and pass on the energy to neighboring particles. This transfer occurs without the actual movement of the particles themselves.
23.
The temperature in which particles would not be moving
Correct Answer
D. Absolute Zero
Explanation
Absolute zero is the temperature at which particles would not be moving. It is the lowest possible temperature, where the kinetic energy of particles reaches its minimum. At this temperature, all molecular motion ceases, and atoms and molecules have no thermal energy. Absolute zero is equivalent to 0 Kelvin or -273 degrees Celsius. 32 degrees Fahrenheit is above absolute zero and particles would still be moving at this temperature.
24.
When using the equation I=V/R, what happens to the current when resistance is doubled?
Correct Answer
A. The current decreases
Explanation
According to Ohm's Law, the equation I=V/R states that the current (I) is inversely proportional to the resistance (R). Therefore, when the resistance is doubled, the current will decrease. This is because as the resistance increases, it becomes more difficult for the current to flow through the circuit, resulting in a decrease in the current.
25.
Current is measured using
Correct Answer
B. Amps
Explanation
Current is measured using amps, which is short for amperes. Amps is a unit of measurement for electric current. It represents the rate at which electric charge flows in a circuit. Coulombs, ohms, and volts are also related to electric current but they are not used to directly measure it. Coulombs measure the quantity of electric charge, ohms measure resistance, and volts measure electric potential difference. Therefore, the correct answer is amps.
26.
As bulbs are added to a ___ circuit, they shine less brightly
Correct Answer
D. Series
Explanation
When bulbs are added to a series circuit, they shine less brightly because the total resistance in the circuit increases. In a series circuit, the current has only one path to flow through, passing through each component in sequence. As more bulbs are added, the total resistance increases, causing a decrease in the current flowing through each bulb. With less current flowing, the bulbs emit less light and appear dimmer.
27.
The circuit shown below is
Correct Answer
C. A parallel circuit
Explanation
The circuit shown below is a parallel circuit because there are multiple paths for current to flow. In a parallel circuit, the components are connected in such a way that the current has alternative paths to follow. This means that if one component fails or is removed, the other components can still function independently. In the given circuit, the two resistors are connected in parallel, allowing current to flow through both of them simultaneously.
28.
What voltage produces a current of 300 amps with a resistance of 20 Ohms?
Correct Answer
A. 6000 volts
Explanation
The correct answer is 6000 volts. According to Ohm's Law, the voltage is equal to the current multiplied by the resistance. In this case, the current is 300 amps and the resistance is 20 Ohms. Therefore, the voltage can be calculated as 300 amps multiplied by 20 Ohms, which equals 6000 volts.
29.
A 9 volt battery produces a current of 45 amperes. What is the resistance?
Correct Answer
C. 0.2 ohms
Explanation
The given answer of 0.2 ohms suggests that the resistance in the circuit is 0.2 ohms. This can be determined using Ohm's Law, which states that resistance (R) is equal to voltage (V) divided by current (I). In this case, the voltage is 9 volts and the current is 45 amperes. Therefore, the resistance can be calculated as 9 volts divided by 45 amperes, which equals 0.2 ohms.
30.
What is an example of a transverse wave?
Correct Answer
C. Ocean wave
Explanation
An example of a transverse wave is an ocean wave. Transverse waves are characterized by their oscillation being perpendicular to the direction of energy transfer. In the case of ocean waves, the water moves up and down (oscillates) perpendicular to the direction in which the wave travels across the surface of the water. This up-and-down motion of water particles is what we observe as ocean waves.
31.
The distance a wave travels in a certain amount of time is the ___
Correct Answer
B. Speed
Explanation
The distance a wave travels in a certain amount of time is determined by its speed. The speed of a wave refers to how quickly it moves through a medium or space. It is measured in units of distance per unit time, such as meters per second. The wavelength, frequency, and amplitude of a wave are all important properties, but they do not directly determine the distance a wave travels in a given time. Therefore, the correct answer is speed.
32.
In this diagram, wavelength is labeled __
Correct Answer
D. D
33.
In this diagram, amplitude is lableled __
Correct Answer
B. B
Explanation
The correct answer is B because in the given diagram, the amplitude is labeled as B.
34.
Sound waves with frequencies above the normal human range of hearing are
Correct Answer
B. Untrasound
Explanation
The correct answer is "untrasound." Sound waves with frequencies above the normal human range of hearing are referred to as ultrasound. Ultrasound waves have frequencies higher than 20,000 Hz, which is the upper limit of human hearing. Ultrasound is commonly used in medical imaging, such as ultrasound scans during pregnancy, as well as in various industrial and scientific applications.
35.
Bats use ____ to locate food and navigate
Correct Answer
C. Echolocation
Explanation
Bats use echolocation to locate food and navigate. Echolocation is a process where bats emit high-frequency sounds and listen to the echoes that bounce back from objects in their surroundings. By analyzing the time it takes for the sound to return and the changes in frequency, bats can determine the location, distance, and size of objects. This ability allows them to navigate in the dark and find their prey with remarkable precision.
36.
Wavelength is measured in
Correct Answer
A. Meters
Explanation
Wavelength is a physical quantity that represents the distance between two consecutive points in a wave that are in phase. It is commonly measured in meters because it represents a physical distance. Hertz is the unit of frequency, not wavelength. Decibels is a unit used to measure the intensity or power of sound. Meters per second is a unit of speed or velocity, not wavelength. Therefore, the correct answer is meters.
37.
Frequency is measured in
Correct Answer
B. Hertz
Explanation
Frequency is a measure of how many cycles or oscillations occur in a given time period. It is commonly used to describe the rate at which a wave, such as sound or electromagnetic waves, repeats itself. Hertz is the unit used to measure frequency, representing one cycle per second. Therefore, Hertz is the correct answer as it is the appropriate unit for measuring frequency.
38.
A wave has a wavelength of 3 m and a frequency of 6Hz. What is the speed of the wave?
Correct Answer
C. 18 m/s
Explanation
The speed of a wave can be calculated by multiplying the wavelength by the frequency. In this case, the wavelength is 3 m and the frequency is 6 Hz. Multiplying these values together gives us a speed of 18 m/s.
39.
The speed of a wave is 20m/s and the frequency is 100Hz. What is the wavelength?
Correct Answer
A. 0.2m
Explanation
The speed of a wave is determined by the product of its wavelength and frequency. In this case, the speed is given as 20m/s and the frequency is given as 100Hz. To find the wavelength, we can rearrange the formula to solve for it. Wavelength = Speed / Frequency. Plugging in the values, we get Wavelength = 20m/s / 100Hz = 0.2m. Therefore, the correct answer is 0.2m.
40.
Why do you hear thunder after you see lightning?
Correct Answer
C. Light is faster than sound
Explanation
When lightning occurs, it produces both light and sound. Light travels at a much faster speed than sound, which is why we see the flash of lightning before we hear the thunder. The speed of light is approximately 299,792 kilometers per second, while the speed of sound is only around 343 meters per second. This significant difference in speed causes the delay between seeing the lightning and hearing the thunder.
41.
____ waves can transfer energy without a medium
Correct Answer
B. Electromagnetic
Explanation
Electromagnetic waves can transfer energy without a medium because they consist of oscillating electric and magnetic fields that can propagate through empty space. Unlike sound waves, which require a medium (such as air or water) to travel, electromagnetic waves can travel through a vacuum, making them capable of transmitting energy over long distances. This property of electromagnetic waves is fundamental to various technologies, including wireless communication, radio waves, and light.
42.
Its harder to hear at the back of the auditorium because
Correct Answer
A. The intensity of the wave decreases as distance from the source increases
Explanation
The correct answer is that the intensity of the wave decreases as distance from the source increases. This is because sound waves spread out in all directions from their source, forming a spherical wavefront. As the wave travels further away from the source, the same amount of energy is spread out over a larger area, resulting in a decrease in intensity. Therefore, the sound becomes quieter and harder to hear as you move farther away from the source.
43.
The loudness of a sound depends upon the wave's
Correct Answer
B. Amplitude
Explanation
The loudness of a sound depends on the wave's amplitude. Amplitude refers to the maximum displacement of particles in a medium from their equilibrium position when a wave passes through. In the case of sound waves, a greater amplitude means a higher intensity, resulting in a louder sound. Therefore, the larger the amplitude of a sound wave, the louder the sound will be.
44.
Sound is a ___ wave
Correct Answer
C. Longitudinal
Explanation
Sound is a longitudinal wave because it travels by compressing and expanding the particles of the medium it is passing through. In a longitudinal wave, the particles of the medium vibrate parallel to the direction of the wave propagation. This means that the particles move back and forth in the same direction that the wave is moving.
45.
All electro magnetic waves have the same ___
Correct Answer
A. Speed
Explanation
All electromagnetic waves, including visible light, radio waves, and X-rays, travel at the same speed in a vacuum, which is the speed of light. This speed is approximately 3 x 10^8 meters per second. The wavelength, frequency, and amplitude of electromagnetic waves can vary, but their speed remains constant. This is a fundamental property of electromagnetic waves and is a key concept in understanding how they propagate through space.
46.
____ waves would cause a sunburn
Correct Answer
C. UV
Explanation
UV waves would cause a sunburn. UV stands for ultraviolet, which is a type of electromagnetic radiation that is emitted by the sun. When the skin is exposed to UV radiation for a prolonged period of time, it can cause damage to the skin cells, leading to a sunburn. UV rays are classified into three types: UVA, UVB, and UVC. UVB rays are primarily responsible for sunburns, as they have a shorter wavelength and higher energy compared to UVA rays. Therefore, it is important to protect the skin from UV radiation by wearing sunscreen, protective clothing, and seeking shade.
47.
____ waves have the shortest wavelengths
Correct Answer
A. Gamma
Explanation
Gamma waves have the shortest wavelengths among the given options. Gamma waves are a type of electromagnetic radiation with high frequency and energy. They have wavelengths shorter than UV, x-ray, and radio waves. Gamma waves are often associated with nuclear reactions, radioactive decay, and high-energy particles. Due to their short wavelengths and high energy, gamma waves have the ability to penetrate through matter and are commonly used in medical imaging and radiation therapy.
48.
A police using a radar gun is using ___ waves
Correct Answer
B. Radio
Explanation
A police using a radar gun is using radio waves. Radar guns use radio waves to detect the speed of moving vehicles. These waves are transmitted from the radar gun and bounce off the target vehicle, then the radar gun measures the time it takes for the waves to return. Based on this time measurement, the radar gun can calculate the speed of the vehicle. Therefore, the correct answer is radio.
49.
Electromagnetic waves with the longest wavelengths have
Correct Answer
B. The lowest frequency
Explanation
Electromagnetic waves with the longest wavelengths have the lowest frequency. Frequency refers to the number of wave cycles that pass a given point in a second. Longer wavelengths correspond to a lower frequency, as the wave cycles take more time to complete. In the electromagnetic spectrum, waves with longer wavelengths include radio waves and microwaves. These waves have lower energy compared to waves with higher frequencies, such as X-rays and gamma rays. Therefore, the correct answer is the lowest frequency.
50.
When light hits and bounces off a bumpy, uneven surface diffuse ____ occurs
Correct Answer
C. Refection
Explanation
When light hits and bounces off a bumpy, uneven surface, it undergoes reflection. Reflection is the process by which light waves bounce off a surface and change direction. In this case, the bumpy and uneven surface causes the light to scatter in different directions, resulting in a diffuse reflection. This is different from regular or specular reflection, where the light bounces off a smooth surface and maintains a clear and organized reflection.