Answer:
B. 560 J
J. 1.2 m
Explanation:
v = Final velocity = 0
u = Initial velocity = 4 m/s
= Coefficient of friction = 0.7
m = Mass of runner = 70 kg
g = Acceleration due to gravity = ![9.81\ \text{m/s}^2](https://tex.z-dn.net/?f=9.81%5C%20%5Ctext%7Bm%2Fs%7D%5E2)
Kinetic energy is given by
![K=\dfrac{1}{2}m(v^2-u^2)\\\Rightarrow K=\dfrac{1}{2}\times 70\times (0^2-4^2)\\\Rightarrow K=-560\ \text{J}](https://tex.z-dn.net/?f=K%3D%5Cdfrac%7B1%7D%7B2%7Dm%28v%5E2-u%5E2%29%5C%5C%5CRightarrow%20K%3D%5Cdfrac%7B1%7D%7B2%7D%5Ctimes%2070%5Ctimes%20%280%5E2-4%5E2%29%5C%5C%5CRightarrow%20K%3D-560%5C%20%5Ctext%7BJ%7D)
The mechanical energy lost is 560 J
Acceleration is given by
![a=-\mu g\\\Rightarrow a=-0.7\times 9.81\\\Rightarrow a=-6.867\ \text{m/s}^2](https://tex.z-dn.net/?f=a%3D-%5Cmu%20g%5C%5C%5CRightarrow%20a%3D-0.7%5Ctimes%209.81%5C%5C%5CRightarrow%20a%3D-6.867%5C%20%5Ctext%7Bm%2Fs%7D%5E2)
From kinematic equations we get
![v^2-u^2=2as\\\Rightarrow s=\dfrac{v^2-u^2}{2a}\\\Rightarrow s=\dfrac{0^2-4^2}{2\times -6.867}\\\Rightarrow s=1.165\approx 1.2\ \text{m}](https://tex.z-dn.net/?f=v%5E2-u%5E2%3D2as%5C%5C%5CRightarrow%20s%3D%5Cdfrac%7Bv%5E2-u%5E2%7D%7B2a%7D%5C%5C%5CRightarrow%20s%3D%5Cdfrac%7B0%5E2-4%5E2%7D%7B2%5Ctimes%20-6.867%7D%5C%5C%5CRightarrow%20s%3D1.165%5Capprox%201.2%5C%20%5Ctext%7Bm%7D)
The runner slides for 1.2 m
The rock had to have undergone chemical weathering due to its change in mineralogical and chemical composition of the rock.
Or
Chemical weathering is when the acid from rain starts to burn through rocks and damage them
It seems that you have missed the necessary options for us to answer this question so I had to look for it. Anyway, here is the answer. What astronomers mean when <span> they say that the sun makes energy by hydrogen burning is that, the Sun is fusing hydrogen into helium and releasing energy. Hope this helps.</span>
Answer:
qualitative observations.
Explanation:
In a qualitative observation, the data that is dealt with is one that has to do with the sense of touch, sight, smell, taste and also hearing. This type of observation does not have anything to do with measurements that involves numbers. Examples of qualitative observation includes shapes, color, gender, citizenship.
1 yard^2 = 0.8361m^2.?
Thank you for posting your question here at brainly. I hope the answer will help you. Feel free to ask more questions.
<span>So he spent (.625 x 400) = $250.00 per m^2. </span>
<span>He paid out (500 x 250) = $125,000 on the deal. </span>
<span>He received (500 / 0.8361) = 598.014592 yard^2 of fabric. </span>
<span>That would have cost (598.014592 x 120) = $71,761.75 locally. </span>
<span>He lost (125,000 - 71,761.75) = $53,238.25 on the deal. </span>
You can rework with the incorrect conversion factor.