Answer:
B. False
Explanation:
All asteroids do NOT orbit the earth. They orbit the asteroid belt, however.
An explosion occurs when the timescale for the energy release by some process is much shorter than the timescale on which a system can adjust to damp the energy release process. In the present day Sun, nuclear fusion is a very slow process: on average it takes many billion years for a proton to fuse with another. This timescale is quite temperature dependent, so you might have thought the centre of the Sun might heat up quickly, leading to a runaway "explosion". However, an increase in temperature leads to an increase in pressure that would expand the Sun, reducing the core density and temperature and decreasing the rate of nuclear fusion again. The timescale for the Sun to react in this way is just millions of years, so this acts like a thermostat that keeps the reactions under control.
Answer:
Explanation:
1. Many issues that affect Africa today are the result of which of the following?
C. European Imperialism
2. A developing country is plagued by malaria. A vaccine for malaria is distributed throughout the country. What will most likely happen next?
C. The country’s infant mortality rate will decrease.
3. Africa has traditionally been a vast, difficult continent to transverse. Today Africa is more open to tourists, trading partners, investment, and urban developments. Which of the following contributions by colonial powers in the region has contributed to this new openness?
C. design and building of transportation infrastructures such as roads, bridges, and railroads
4. Which of the following is an example of a “Pandemic” disease in Africa?
B. AIDS
Answer:
<em>They orbit the Sun.</em>
<em></em>
Explanation:
Asteroids are small planetary bodies, too small to be classified as a planet. Asteroids are made up of rocky materials, and they orbit the sun. In our solar system, a vast number of asteroids exists together in the 'great asteroid belt' a region between the orbit of Mars and Jupiter. A comet is a ball of frozen gas, rocks and dusts, that travels around the sun in the solar system. Comets can be as big as a small town. When the orbit of a comet brings it close to the sun, it melts, leaving a trail of gas behind it. This trail of gas is the characteristic long tail of a wishing star seen in the sky in some clear night.
<em>The common property of a comet and an asteroid is that they both travel around the sun in the solar system, just like every other planetary body in the solar system.</em>
