Answer:
The mass of the block m is:
Explanation:
Let's analyze the block by parts
For the block M
(1)
Where:
- T is the tension
- W(x) is the component of the weight in the x-direction
- F(f) is the friction force
For the block m
(2)
Now, let's combines equation (1) and (2):
Finally, let's solve it for block m.
I hope it helps you!
<h2>
Answers:</h2>
-The first direct detection of gravitational waves came in 2015
-The existence of gravitational waves is predicted by Einstein's general theory of relativity
-Gravitational waves carry energy away from their sources of emission
<h2>
Explanation:</h2>
Gravitational waves were discovered (theoretically) by Albert Einstein in 1916 and "observed" for the first time in direct form in 2015 (although the results were published in 2016).
These gravitational waves are fluctuations or disturbances of space-time produced by a massive accelerated body, modifying the distances and the dimensions of objects in an imperceptible way.
In this context, an excellent example is the system of two neutron stars that orbit high speeds, producing a deformation that propagates like a wave,<u> in the same way as when a stone is thrown into the water</u>. So, in this sense, gravitational waves carry energy away from their sources
.
Therefore, the correct options are D, E and F.
Answer:
<em>The frequency changes by a factor of 0.27.</em>
<em></em>
Explanation:
The frequency of an object with mass m attached to a spring is given as
= 
where
is the frequency
k is the spring constant of the spring
m is the mass of the substance on the spring.
If the mass of the system is increased by 14 means the new frequency becomes
= 
simplifying, we have
= 
= 
if we divide this final frequency by the original frequency, we'll have
==>
÷
==>
x
==> 1/3.742 = <em>0.27</em>
Answer:
Explanation:
Let lift force F be created by propellers at angle of Ф with the horizontal .
The vertical component of this force will balance the weight of helicopter and horizontal component will balance the air resistance .
F sinФ = mg = 2750 x 9.8 = 26950 N
F cosФ = 7510 N
Squaring and adding ,
F² = 26950² + 7510²
= 726302500 + 56400100
= 782702600
F = 27976.82 N .
From the law of atmosphere

Where
= constant and is number density where the height y = 0cm
= Number density at height y=3cm
Kb = Boltzmann constant 


Re-arranging the equation to have the value of the gravity,


Since it is 30% of value above surface, therefore 






Therefore the correct answer is C.