1. When you rub a balloon and bring it closer to a wall, it sticks to it. Give reason for it.
2. Why is a crackling sound heard on removing sweaters?
3. The sound of the lightning is heard after lightning appears. Give reason.
4. Which of the following earthquakes will have a more devastating effect 5.0 or 7.0 on Richter
scale? Give reason.
Answers
1)Static Electricity is a familiar electric phenomenon in which charged particles are transferred from one body to another. When you rub your hair or a sweater against a balloon, charge transfer occurs, and Static Electricity is produced. In simpler terms, if you rub a balloon against your sweater, the balloon will steal electrons from the sweater, which leaves the sweater positively charged and the balloon negatively charged. The balloon will most likely be attracted back to the sweater because opposite charges attract. The reason that the balloon will stick to the wall is because the negative charges in the balloon will make the electrons in the wall move to the other side of their atoms (like charges repel) and this leaves the surface of the wall positively charged. Because opposite charges attract, the negatively charged ballon will be attracted to the positively charged surface of the wall.
Something interesting that I stumbled upon while doing this research was some different materials that cause a lot of static electricity are rabbit fur, human hair, cat fur, glass, and dry human skin!
2)Woollen or synthetic sweaters develop static charges (electrons) on them due to friction. While taking off our sweater, these charges move in streams between the sweater and our body, i.e. electric discharge takes place. This results in crackling sound and miniature sparks of lightning.
3)Speed of light (3\displaystyle \times 10^{8}m/s×10
8
m/s) is much more than the speed of sound (330 m/s) in air So flash of lightning is seen before the sound of thunder is heard.
4)There are three main types of fault, all of which may cause an interplate earthquake: normal, reverse (thrust), and strike-slip. Normal and reverse faulting are examples of dip-slip, where the displacement along the fault is in the direction of dip and where movement on them involves a vertical component. Normal faults occur mainly in areas where the crust is being extended such as a divergent boundary. Reverse faults occur in areas where the crust is being shortened such as at a convergent boundary. Strike-slip faults are steep structures where the two sides of the fault slip horizontally past each other; transform boundaries are a particular type of strike-slip fault. Many earthquakes are caused by movement on faults that have components of both dip-slip and strike-slip; this is known as oblique slip.
Reverse faults, particularly those along convergent plate boundaries, are associated with the most powerful earthquakes, megathrust earthquakes, including almost all of those of magnitude 8 or more. Strike-slip faults, particularly continental transforms, can produce major earthquakes up to about magnitude 8. Earthquakes associated with normal faults are generally less than magnitude 7. For every unit increase in magnitude, there is a roughly thirtyfold increase in the energy released. For instance, an earthquake of magnitude 6.0 releases approximately 30 times more energy than a 5.0 magnitude earthquake and a 7.0 magnitude earthquake releases 900 times (30 × 30) more energy than a 5.0 magnitude of earthquake. An 8.6 magnitude earthquake releases the same amount of energy as 10,000 atomic bombs like those used in World War II.