Hydrogen gas is harmless to your feet so since you don’t need protection against it that seems the best answer.
Answer:
The ocean tides on earth are caused by both the moon's gravity and the sun's gravity. ... Even though the sun is much more massive and therefore has stronger overall gravity than the moon, the moon is closer to the earth so that its gravitational gradient is stronger than that of the sun.
density of water = 
velocity of flow = 
radius of pipe = 
Height of second floor = 
Now we can use here Bernuoli's Equation to find the speed of water flow at second floor



Now in order to find the radius of pipe we can use equation of continuity



So radius of pipe at second floor is 0.034 meter
Answer:
C
Explanation:
Sound waves speed up noticeably when moving through a solid or liquid, because all it is is just particles colliding; and particles are way closer together with those states of matter.
The speed of light can change when moving through different substances, but this is dependent on complicated factors such as frequency, polarization, intensity, et. cetera
The important part is that it does change speed, so your answer is C.
Hope this helps!
We'll look at two properties:
1. The variation in temperature
2. The material's heat transfer coefficient
By taking an example;
Use a circular rod made of a certain material (for example, steel) that is insulated all the way around.
One end of the rod is immersed in a huge reservoir of 100°C water, while the other is immersed in water at 40°C. The cold water is kept in an insulated cylinder on both sides. The temp of the chilly water is measured using a meter as a time - dependent.
Conclusion of experiment;
- Heat is transferred from a hot location to a cooler region.
- Whenever heat is applied to a body, its thermal power rises, and its temperature rises.
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