Answer:
After sufficient thickness of ice is formed it prevents further loss of heat from the bottom layers of water. This is why fishes and other aquatic animals and plants can survive in ponds and other water bodies even when the atmospheric temperature reaches or is well below 0 degrees.The anomalous expansion of water helps preserve aquatic life during very cold weather. When temperature falls, the top layer of water in a pond contracts becomes denser and sinks to the bottom. ... Thus, even though the upper layer are frozen, the water near the bottom is at 4°C and the fishes can survive in it easily.
Answer:
(a) 
(b) 15 hours
Explanation:
half life, T = 12 hours
No = 19 g
(a) Let N be the amount remaining after time t.
Let λ be the decay constant.

The equation of radioactivity used here is given by


(b) N = 8 gram
Substitute the values in above equation

λ = 0.0577 per hour
So, 

Take natural log on both the sides
- 0.0577 t = - 0.865
t = 15 hours
Answer:
1 solar masses
Explanation:
-Sirius has to maintain equilibrium with it's companion.
-Let x be the mass of Sirius and y be the mass of it's companion.
-From the question, we know that Sirius is 2.35 times heavier than it's companion:

Hence, the mass of it's companion is 1 solar masses
Answer:
The main purpose of the turbine in the turbojet engine is to Drive the compressor.
Explanation:
This doesnt make sense. 2g<span>Δym is simply an equation. </span>