Physics for Teens Trivia Quiz

Answer: Alternate the current

Electromagnets have many uses and are all around us. They are found in electric motors, loudspeakers and door bells. Very powerful ones are used in industry to lift and move large metal objects such as vehicles in a scrap yard.

Answer: Steel

Sound travels through an object by transferring between molecules. The speed of the sound is dependent on how tight the bonds between the molecules are. The less 'elastic' a material is, the faster the sound moves. For the quoted examples the relevant speeds are: steel, 5100 m/s (meters per second); gold, 3240 m/s; water, 1493 m/s; air, 343 m/s. Diamond allows sound to travel at 12000 m/s which equates to 27000 mph.

Answer: Audible range

The range of audible frequencies, generally 20 Hertz to 20,000 Hertz, varies from person to person and can be affected by things such as age. The sound is collected by the ear and passes along the ear canal to the ear drum. As this membrane vibrates it transfers the movement to the three smallest bones in the body, commonly called the hammer, anvil and stirrup. From here it moves into the cochlea and then along the auditory nerve to the brain to be interpreted.
One Hertz (Hz) is equal to one cycle per second.

Answer: Refraction

It is refraction that causes sticks to appear bent when they are in water and for objects to appear in a different position to where they actually are. Refraction does not occur when the object is viewed from directly above.

Answer: Microwaves

Wavelength is how a wave,(sound,light,or any other type) is measured in terms of the distance between, for example, the tops of the wave. A long wavelength, as far as sound is concerned, has a lower frequency and 'tone'. Frequency is how many times in a given period the same thing happens.
The wavelengths,in order, from the lowest to the highest frequency (and longest to shortest wavelength) are:
Radio
Microwaves
Infra-Red
Visible light
Ultra-violet
X-rays
Gamma rays

A way to remember them is:
Rabbits
Mate
In
Very
Unusual
eXpensive
Gardens

Answer: Delta

Alpha radiation is very weak, compared to other types. It can be blocked by something as simple as a sheet of paper. Beta radiation is stronger and can penetrate further. Ordinary clothing offers some protection from Beta particles. Gamma rays, and the associated X-rays, need a dense material to stop them. It is for this reason that when you have an X-ray taken in hospital, the staff are hidden behind a shield.
Delta particles do not, at this time, exist.

Answer: Radon gas

Radon gas is a naturally occurring radioactive gas that is formed by the decay of the element radium. It is one of the heaviest things that remains as a gas under normal conditions. High levels of radon are found where the bedrock of the area is granite.

In the UK radon accounts for around 50% of the background radiation level. Cosmic rays account for around 10%, buildings and the ground add 14%. Nuclear power plants and weapons only account for 0.3% of the total of background radiation.

Answer: False

The mass of an object stays the same, but the weight can change if the object is moved to a place where gravity is stronger or weaker.If the object is moved to the moon it's mass remains the same but it weighs less because gravity is weaker. Mass is measured in kilograms and weight is measured in Newtons. To find the mass of an object, multiply its weight, in kilograms, by 10.

Answer: Convection

Convection occurs when particles with a high amount of thermal energy move and take the place of particles with less energy. The same effect occurs in gases. This is how a radiator helps to heat a room. Gas particles are warmed up and rise, as they cool they sink lower and are heated again by the radiator. They then rise again and the cycle continues.
Conduction happens in solids when particles collide with each other and transfer heat. Radiation does not involve moving particles and so can work in space (this is how we feel the heat from the sun).
Evaporation is a change of state from a liquid to a gas.

Answer: Potential

Potential energy is stored energy. It isn't being used, but may be in the future. Kinetic energy is energy in a moving object. Chemical energy is stored in the bonds between an objects molecules and is released during a chemical reaction. Elastic energy is a form of energy that is found in a coiled spring and is a type of potential energy.