Why can't we be certain that the Andromeda Galaxy exists today?
What will be an ideal response?
Since it lies 2.5 million light-years distant, the most recent image we have is still 2.5 million years out of date, so we cannot prove it is still there. It probably is, though.
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Angular and Linear Quantities: A rolling wheel of diameter of 68 cm slows down uniformly from 8.4 m/s to rest over a distance of 115 m. What is the magnitude of its angular acceleration if there was no slipping?
A. 1.8 rad/s2 B. 0.90 rad/s2 C. 5.7 rad/s2 D. 11 rad/s2
Which of the following is TRUE?
A. Mercury has a very thick atmosphere made mostly of carbon dioxide. B. Venus has no volcanos on its surface. C. Mercury rotates exactly one and a half times for every one revolution around the Sun. D. The runaway greenhouse effect causes the present temperatures on Mars to exceed those on Earth. E. The average surface temperature of Venus is about 30 degrees Fahrenheit.
For a particular spring, the spring constant
A. Increases as the spring is stretched B. Increases as the spring is compressed C. Decreases as the spring is compressed D. Is the same regardless of stretching or compressing
Air near the equator averages higher temperatures than air near the poles because
A) polar air is cooled by ice and snow on the ground. B) solar energy is readily absorbed due to increased levels of CO2 and water vapor in the air. C) sunlight falls in a more vertical position at the equator than near the poles. D) the oceans near the equator are warmer than those near the poles.