You haven't told us anything about the detectors being used. We don't know how the sensitivity of the detector is related to the total number of photons absorbed, and we don't even know whether you and your friend are both using the same type of detector.
All we can do, in desperation, is ASSUME that the minimum time required to just detect a star is inversely proportional to the total number of its photons that strike the detector. That is, assume . . .
(double the number of photons) ===> (detect the source in half the time) .
-- The intensity of light delivered to the prime focus of a telescope is directly proportional to the AREA of its objective lens or mirror, which in turn is proportional to the square of its radius or diameter.
So your telescope gathers (0.18/0.05)² = 12.96 times as much light as your friends telescope does.
-- So we'd expect your instrument to detect the same star in
(119.5 min) / (12.96) = <em>9.22 minutes .</em>
We're simply comparing the performance of two different telescopes as they observe the same object, so the star's magnitude doesn't matter.
Answer:
Increasing temperatures evaporate water faster, causing an increase in salinity.
Explanation:
When the water molecules of the ocean become heated, they expand. ... Since warmer water thus can hold more salt and other molecules than cold water; it can have a higher salinity.
Answer:

Explanation:
#Using the conservation of momentum , momentum before equals momentum after(
.
-Initial speed is 5.2m/s while the cart is at rest. After, the velocity will be of a combined(bag+cart) mass.
Hence:

Hence, the final velocity of the cart and bag is 1.77m/s
D. Yuri Gagarin
(Typing this to circumnavigate the 20 character minimum requirement)
A flow of electric charge from one place to another is electric 'current'.
Also:
When you post a multiple-choice question,
please post the choices along with it.
Thank you.