If we double the diameter of a telescope's mirror, what happens to its light-gathering ability? View Available Hint(s) If we dou
1 answer:
Answer:
Light-gathering ability quadruples.
Explanation:
The light-gathering ability of a telescope depends on the area of the mirror, which is the surface presented to the light. Since these mirrors are circular (diameter is mentioned), we need to know what happens with the area of it when its diameter is doubled.
If r is the radius and d the diameter of a circle, its area will be:
We want to know now what happens if we double the diameter to 2d, so we calculate the new area A':
Which is 4 times greater than the original area A, so we conclude that its light-gathering ability quadruples.
You might be interested in
Answer:
Reactance
Explanation:
In an AC circuit, the capacitive reactance of a capacitor is given by:
where
f is the frequency of the AC current
C is the capacitance of the capacitor
The reactance of the capacitor tells somehow the "resistance" of the capacitor to the passage of current through it. In fact:
- When the frequency of the AC current is zero (this means, we are in regime of DC current), the reactance becomes infinite, and this is true because the capacitor does not let the current pass through it)
- When the frequency of the AC current tends to infinite, the reactance becomes zero, and this is true because in this case the current changes direction so fast that the capacitor has not enough time to "block" the current, so the current almost no feels the presence of the capacitor.