Answer:
The tension on the clotheslines is 
Explanation:
The diagram illustrating this question is shown on the first uploaded image
From the question we are told that
The distance between the two poles is 
The mass tie to the middle of the clotheslines 
The length at which the clotheslines sags is 
Generally the weight due to gravity at the middle of the clotheslines is mathematically represented as
let the angle which the tension on the clotheslines makes with the horizontal be
which mathematically evaluated using the SOHCAHTOA as follows

=> ![\theta = tan^{-1}[\frac{4}{6} ]](https://tex.z-dn.net/?f=%5Ctheta%20%3D%20%20tan%5E%7B-1%7D%5B%5Cfrac%7B4%7D%7B6%7D%20%5D)
=> 
So the vertical component of this tension is mathematically represented a

Now at equilibrium the net horizontal force is zero which implies that

=> 
substituting values

substituting values


The work done was done by friction to keep the crate from moving as the truck came to a stop is 20,000 J.
<h3>
Work done by friction to prevent the crate from moving</h3>
The work done is determined by applying the principle of conservation of energy.
W = K.E
W = ¹/₂mv²
where;
- m is mass of crate
- v is speed of the crate with respect to the truck = 20 m/s
W = ¹/₂(100)(20²)
W = 20,000 J
Thus, the work done was done by friction to keep the crate from moving as the truck came to a stop is 20,000 J.
Learn more about work done here: brainly.com/question/8119756
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Answer:
A. Extracting mineral resources with modern mining equipment removes fertile topsoil.
Explanation:
Mining is defined as the process that involves the extraction of valuable minerals from large amounts of waste rock.
Progress in engineering has affected the natural environment and mining is one of the best examples of this. The use of modern mining equipment removes fertile topsoil and highly influences the fertility of the soil. It is hard to reconstruct topsoil and modern mining equipment continuously damaging soil fertility.
Hence, the correct answer is "A. Extracting mineral resources with modern mining equipment removes fertile topsoil."
50N.
The magnitude of the reaction to any force is equal to the magnitude of the first force. (See Newton #3.)
Kinetic energy is not a vector. This is because it is not a directed quantity. The other 3 have a sense of direction.