GS103 New Quiz

1. What would happen to a bar magnet, in regards to the poles, if you were to break it in half?

There will be two bars both having positive and negative poles. There is no magnetic unipole in nature.
2. Would you expect to find direct or alternating current in (a) the filament of a light bulb in your home? (b)the filament of a light bulb in a car? (c) the output of a battery charger?

a) alternating current

b) direct current (current from car battery)

c) direct current (need to match the current in the battery)

3) Describe the properties of transverse and longitudinal waves and how they differ from each other.

-Transverse waves always are perpendicular to the direction of propagation. They are associated with the property of cutting forces in the propagation medium.2 dimensional transverse wave exhibit the phenomena of polarization. Examples of transverse wave is seismic secondary wave and electromagnetic wave-Longitudinal waves always have the same direction of vibrating as the direction of propagation. They are also named as compressional waves in mechanics.example of longitudinal waves are sound waves and pressure waves.

4) Two sound waves travel in air. The first wave has a higher frequency than the second. Which wave has a longer wavelength? How do you know? The wavelength is directly proportional to the period of the wave, hence inversely proportional to its frequency. They are also directly proportional to the speed of the wave. The wave having a longer wavelength will have a higher frequency.
5) A stationary individual hears the whistle of an approaching train. As the train approaches, how would the frequency of the noise produced by the whistle sound to the individual? How would it change as the train moved away? As the train approaches the Doppler effect will shift the frequency of the whistle towards higher frequency. As the train moves away the same effect will shift the frequency of the sound towards lower frequencies.

6) Give an example of a type of wave that can travel through empty space. What is an example of a wave that requires a medium to move through?

An example of first type of wave is the electromagnetic wave (or light). An example of the second type of wave is the sound.

7) You are standing on a pier and want to spear a fish that swims by. Should you aim above, below, or exactly where the fish seems to be? What if you swimming under water and want to spear a fish? The angle of refraction of light into water is lower than the angle of incidence. This means the being above water you should aim below the position where the fish seem to be (the real position of the fish is above the position where it seems to be). Under water you should aim exactly where the fish seems to be, because light travels in a straight line.

8) Find the number of neutrons and protons in each of the following nuclei:

a) Li, Z= 3 protons, Z-A=3 neutrons

b) C, 6 protons, 7 neutrons

c) P, 15 protons, 16 neutrons

d) Zr, 40 protons, 54 neutrons

9) If a radioactive substance’s half-life is 64 days, how much is left after 128 days?

After 64 days there will be only half of its initial mass. This means that after another 64 days (128 days in total) there will be only ¼ (one quarter) of its initial mass.

10. Describe how electrons, protons, and neutrons are structured within an atom. What are the charges of each?

Electrons are negative, protons are positive and neutrons are neutral. The protons and neutrons are bonded togheter by the strong and weak nuclear forces forming together the nucleus of the atom. A region of space less than 1-0.1% of the entire atom. The electrons are grouped together outside the nucleus in the remaining space of the atom forming the so called shells. Every electron shell has a certain unchanged level of energy.