Physics Trivia Questions and Answers
Physics Trivia Questions Part 1
1. A rocket is launched at a speed of 10 kilometres per second. How far will it travel in 1/2 minute?
Answer: 300 km.
A definition of speed n physics is as follows:
Speed in physics is defined as the distance travelled divided by the time it took to travel that distance.
Conceived as a derived quantity, speed has both magnitude and direction. Any object has a “true” speed, usually referred to as “speed relative to reference frame”. Any object also has an observed or measured speed, usually referred to as “speed relative to observer”. It is important that the reference frame in which the object is moving be specified. A common misconception in understanding of relativity is that there exists only one single universal reference frame for all observers and measurement procedures. The actual situation can be more complex than this.
2. BAC stands for:
Answer: Blood Alcohol Content.
Blood alcohol content/concentration (BAC) is a measurement of the amount of alcohol in a blood sample. The BAC depends on the amount of alcohol consumed, body weight, sex, and percentage of body water. A low BAC level can be achieved by drinking slowly over several hours or mixing alcohol with drinks that contain a high percentage of non-alcoholic beverages. A high BAC can result from drinking large amounts of hard liquor (usually distilled spirits), fast consumption of alcoholic beverages and not eating food during the period when alcohol is being consumed.
Blood Alcohol Concentration and Breath Testing
There are two types of blood alcohol tests: the blood test and the breath (or “breathalyzer”) test. The results of these two tests do not necessarily concur. For example, in one study, the breath tests revealed alcohol was present in 71 percent of those who had a blood alcohol reading of 0.10 or more but less than 8 percent whose BAC was only 0.05 or above. In another study, 50 percent were found to be positive for alcohol on the breath tester when their blood alcohol level was 0.06 or higher but not above 0.
3. The density of water in g/mL is:
Density is a measure of mass per unit volume. The density of most materials decreases with increasing temperature. This causes the volume to increase, which increases the pressure at a given amount of total mass. For example, consider a ship filled with liquid. If the temperature is higher, then the liquid will be less dense (i.e. more steam and less liquid). Therefore, it could contain more mass even though it’s occupying the same volume as before (the ship). This greater amount of mass exerts more force on the bottom of the ship.
4. The rule to calculate momentum is:
Answer: Mass X velocity.
What is momentum? The definition of momentum is the product of the mass and velocity of a body. It’s symbolized by a capital M in lowercase. The momentum of a system of objects is equal to the product of their masses and the magnitudes of their velocities.
5. The density of carbon dioxide gas is greater than that of air. In a container of air, carbon dioxide gas will be found:
Answer: At the bottom of the container.
The fact that the density of carbon dioxide gas is greater than that of air is used to explain why it does not mix very well and why it stays near the ground. Carbon dioxide is a greenhouse gas because of its ability to absorb certain wavelengths of infrared light which heats the atmosphere near the ground and in turn heats the earth itself.
6. Four-wheel-drive owners let air out of their tyres before driving on sand. This is because:
Answer: The contact area between the tyres and the sand is increased.
Letting the air out of the tyres makes driving through sand easier because the traction is increased and the sand is more compressed and therefore harder to push through.
The science behind this is that the more the tyres press into the sand, the more they sink; this makes it easier for the tyres to continue moving because they are in an almost stable position.
This trick can also be thought of as a ‘double-whammy’. Not only does it make driving easier, it can also stop you from getting stuck in such soft sand as well, although you will probably have to re-inflate your tyres afterwards.
7. Two identical blocks of wood are placed side by side on a table. One lies on its larger side, and the other stands on its smaller end. Which is exerting the greatest pressure on the table?
Answer: The one standing on its end.
The contact area of a block is directly related to its pressure. The two blocks have the same weight. Thus, they have the same downward force on the table. The only factor differentiating them is their contact area; this is where they have their greatest differences in pressure.
8. An example of gravitational potential energy is the energy of:
Answer: Any object at a height.
Gravitational potential energy is the energy an object has by virtue of its position, and is sometimes referred to as ‘potential’ or ‘potential energy’. It arises in classical mechanics from the force of gravity acting on a body and the body’s consequent acceleration. The term “gravitational potential” was proposed by Gunter Ritter von Zach (1856–1920) in 1887.
Gravitational potential energy is equal to the work needed to move the object from a reference location to its present position, plus additional, non-conservative work due to friction.
9. A weightlifter lifts barbells of 200 Newtons above his head to a height of 2 metres. How much work does he do?
Answer: 400 Joules.
The weight is 200 newtons, the height he raises it to (the highest point) is 2 metres. It’s a straight line so displacement = 20 metres. Therefore work done = force x distance which gives us W = 200 x 20 which equals 4000 joules
10. The small groups of atoms that behave like small magnets inside a large magnet are called:
Domain walls are the boundaries between adjacent domains. Domain states refer to the lowest energy state for a macroscopic domain and are characterized by the fact that there is zero magnetization within the domain.
Physics Trivia Questions Part 2
11. The magnetic field of a magnet:
a) is always as strong anywhere around a magnet
b) only exists on the poles themselves
c) weakens as the distance from the magnet increases
To test this, a group of scientists built a long straight coil of wire around the outside of their experimental room, and then arranged for it to move with respect to a magnet. The coil was connected to an ammeter, which allowed them to monitor the current in the coil.
The magnet was placed underneath the ammeter. The group positioned 3 metres away from the magnet. The scientists found that when they moved the coiled wire closer towards the magnet, the ammeter reading increased. Moving it away from the magnet caused it to decrease. This relationship held true no matter how far away from or close to the magnet they were.
12. The instrument used to measure current is the:
An ammeter in series with a load (in this case a charging resistor) showing total current. The instrument displays the sum of the product of current and resistance (I2R). In this example R is 4 ohms and I is 10 amperes so the total current divides into 20 amperes divided by 4 ohms = 5 amperes through each branch.
13. The visible spectrum of light from the longest to shortest wavelength is:
Answer: red, orange, yellow, green, blue, indigo, violet.
The spectrum of visible light is the region in which visible light wavelengths are found, also known as the electromagnetic spectrum. The human eye can only see a small portion of the entire electromagnetic spectrum, and so it is referred to as vision or the visible spectrum. The other wavelengths that exist are invisible, such as those used in x-rays and gamma rays.
14. When light rays travel at a critical angle through an object such as optical fibre, they are:
Answer: Totally internally reflected.
This phenomenon is commonly used for optical communication systems and complex spectroscopy applications.
Observation of a new type of electromagnetic field distribution in which light rays travel at a critical angle through a material with negative refractive index, such as certain photonic crystals and metamaterials, resulting in zero total internal reflection.
15. There is no sound in a:
a) solid b) vacuum c) Liquid
This is because there is no medium to propagate it. Sound requires a medium through which to travel and therefore cannot exist in a vacuum. This means that the sound in space as we know it, which is actually electromagnetic waves, cannot be heard by humans because we have nothing to convert them into audible sound waves. So technically there has never been any sound in space since nothing has ever been able to make any noise there.
16. Loudness of sound is measured in:
What is decibels?
Decibels (dB) is the unit of measurement used for measuring and comparing the level of sound. Decibels are logarithmic in scale, a measurement system in which larger numbers represent greater magnitude or power. These numbers reflect how loud the sound is, not how far away it may be. There are two scales to measure decibels:
Tone-decibel scale – used to measure low-level sounds such as sounds that are heard day-to-day; from a whisper to a lawn mower on low speed.
17. An example of a wheel and axle is:
Answer: A doorknob.
wheel and axle is a device that converts rotational motion to linear motion, or a device that converts torque to linear force. It consists of a wheel hub and an axle mounted together so they rotate as one unit. The wheel is attached to the axle with a bearing, or more properly called a pivot, which allows the wheel to rotate around the axle. The most basic designs consist of a frame or rigid structure with a wheel and an axle attached rigidly to opposite ends of the frame so they rotate together.
18. An example of a second-order lever with fulcrum, load and effort in that order is:
Answer: A wheelbarrow.
A wheelbarrow is a small cart that has handles on two or four sides, and wheels. A wheelbarrow is used to carry shovels, rakes and other tools. Wheelbarrows are also used to move loose materials such as sand, gravel or building material. Some towable wheelbarrows are mounted on a low-boy trailer base so that the operator can wing them with a tractor/truck behind the operator in order to more easily transport extremely heavy materials such as dirt, sand or concrete. These are typically referred to as “Lowboys” when the wheels are off the ground.
19. The volume of rock music is about:
Answer: 100 decibels.
100 decibels is about 10 times louder than a garbage truck.
Groups of adolescents exposed to 100 decibels (dB) or more have up to four times as many hearing losses as those exposed to less than 90 dB, according to a study appearing in the October issue of the Archives of Otolaryngology-Head & Neck Surgery, one of the JAMA/Archives journals.
20. Gravitational acceleration is:
Answer: Rate of change of speed of falling objects.
Gravitational acceleration, also known as gravitational force, is the [main] force responsible for the gravitational attraction between objects with mass, specifically on planets and similar bodies where the effect of air drag can be ignored. It was first accurately measured by Henry Cavendish in 1798. The SI unit of g is m/s2 (or alternatively kgf·m/s2).