<span>We know that pressure is the force applied into a surface, in our case the wall of the room, so then first we will calculate the surface of this wall:
S = 2.2 * 3.2 = 7.04 m2
Then we also know the atmospheric pressure in normal conditions is 1 atm. That is the same 1 atm = 101325 Pascals or 101325 N/m2
Now we need to use the formula : P = F/S where P is pressure, F is force and S is surface to calculate the force:
F = P * S = 101325 * 7.04 = 713,328 Newtons
Conclusion: the force acts on the wall due the air inside the room is 713,328 N</span>
Answer:

Explanation:
Let the height of the ladder be L

Also:
- Let

- Let

When the ladder leans against the wall, it forms a triangle and the length of the ladder forms the hypotenuse.
So, we have:
--- Pythagoras Theorem
When the base is 9ft from the wall, this means that:

Substitute 9 for x and 10 for L in 


Make
the subject


Make y the subject


<em>Hence, the true distance at that point is approximately 4.36ft</em>
The correct answer that would best complete the given statement above would be the second option. A screw is an inclined plane wrapped around a cylinder. <span>The efficiency of a screw is low because there is more input than output. In other words, it is because of friction. Hope this answer helps.</span>
Incomplete question as the unit of volume is not written correctly.So the complete question is here:
A straightforward method of finding the density of an object is to measure its mass and then measure its volume by submerging it in a graduated cylinder. What is the density of a 240-g rock that displaces 89.0 cm³?
Answer:

Explanation:
Given data
Mass m=240g
Volume V=89.0 cm³
To find
Density d
Solution
If rock displaces 89.0 cm³ of water means volume of rock is also 89cm³
So

working...
Sound wave needs medium to travel
as energy which travels in this wave is because of transfer from one particle to another particle
If there is no medium then energy can not be transferred and sound wave will not travel
so in vacuum we can not listen sound
similarly here air is removed it means there is no medium inside the jar to travel the sound and hence we can not hear it
Option B is correct
Without air, the sound waves cannot travel to the ear.