Answer:
342 m/s
Explanation:
The velocity of sound in air is approximated as:
v ≈ 331.4 + 0.6 T
where v is the velocity in m/s and T is the temperature in Celsius.
At T = 18:
v ≈ 331.4 + 0.6 (18)
v ≈ 342.2
The velocity is approximately 342 m/s.
In almost every case in nature, adding heat to a liquid
causes the density of the liquid to decrease. That is,
when the liquid gets warmer, it expands and occupies
more space.
The one big exception to this rule is water !
Starting with a block of ice at zero°C (32°F), as the ice melts,
becomes water at zero°C, and all the way to 4°C (about 39°F),
its density increases all the way. That is, it shrinks and occupies
less volume as it goes from ice at zero°C to water at 4°C.
This sounds like an interesting but insignificant quirk ... until
you realize that if water didn't do this, then life on Earth would
be impossible !
Answer:
when we lower a bucket into a well to fetch water, the work done by gravity is positive since force and displacement are in the same direction.
Explanation:
Answer:
4.96 × 10⁵ Pa
Explanation:
F = mg
This force is evenly distributed on the three leg
radius, r = d/2
= 2.8 / 2
= 1.4 cm = 0.014 m
total cross sectional area of the three legs, A = 3*pi*r^2
Pressure due to weight,
P = Weight/A
P = 4.96 × 10⁵ Pa
