I think it's D cuz D is the heliocentric theory
Answer: 80 Newton
Explanation:
Initial velocity of ball = +20 m/s.
Final velocity of ball = -20 m/s
Mass of ball = 0.1kg
Time taken = 0.05 seconds
Average force = (Change in momentum of moving ball / Time taken)
Since, change in momentum = Mass (final velocity - initial velocity)
Change in momentum =0.1 x (-20 - (+20))
= 0.1 x (-20-20)
= 0.1 x (-40)
= -4.0 kgm/s
Then, put -4.0 kgm/s in the equation of force when Average Force = (Change in momentum / Time taken)
= (-4.0kgm/s / 0.05 seconds)
= 80Newton (note that the negative sign does not reflect on the magnitude of force)
Thus, the average force exerted on the ball is 80N
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


Answer:
120.03 points on it and its 1234.4KG on the earth