Answer:
im not sure, but i think...
Explanation:
the harpy eagle???
D. used by the entire scientific community
B. more accurate system of measurement
Answer:
2324 J
Explanation:
The formula for work is:

where
is the force applied, and
is the distance moved, in this case 
and we need to find 
Since the crate is not moving up or down, we conclude that the <u>normal force must be equal to the weight </u>of the object:

where
is the normal force and
is the weight, which is:
, where g is the gravitational acceleration
and
is the mass
.
---------
Thus the normal force is:

Now, the force due to the friction is defined as:

where
is the coefficient of friction, 
So, for the crate to move, the force applied must be equal to the frictional force:

And now that we know the force we can calculate the work:

substituting known values:

Answer:
convection
Explanation:
By the actual movement of molecules
With the use of below formula, at 879 °C, velocity will be double the velocity at 15 °C.
<h3>
What is the relationship between Velocity and sound ?</h3>
The velocity of sound waves in air is proportional to the square root of Thermodynamic temperature. That is, V = K
Given that the temperature at which the velocity of sound in air is twice its velocity at 15°C, Let us make use of the formula;
(v2/v1) = √(T2 / T1)
Where
- T2 = final absolute temperature
- T1 = initial temperature.
Recall that absolute temperature = °C + 273.
If v2 = 2 × v1 and temperature in degree Celsius = 15°C, then,
Temperature in Kelvin K = 15 + 273 = 288
Substitute all the parameters into the formula
(2 × v1)/v1 = √(T2/288)
2 = √ (T2 /288)
Square both sides
4 = (T2/288)
T2 = 4 × 288
T2 = 1152K
Temperature in degrees Celsius = 1152 - 273 = 879 °C.
Therefore, at 879 °C, velocity will be double the velocity at 15 °C.
Learn more about sound waves here: brainly.com/question/13105733
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