<h2>
Answer:</h2>
The area of the top surface of the washer is: 160.14 square mm.
<h2>
Step-by-step explanation:</h2>
The top of the surface is in the shape of a annulus with a outer radius of 10 mm and a inner radius of 7 mm ( since the diameter of the hole is: 14 mm and we know that the radius is half of the diameter)
Now, we know that the area of the annulus region is given by:
where R is the outer radius and r is the inner radius.
Here we have:
Hence, we have:
Answer:
The 2nd one.
Step-by-step explanation:
I honestly don’t know man but don’t worry, if you get a bad score it won’t matter in 30 years :)
<span>1/r + 2/1-r = 4/r^2
1-r+2r/r(1-r)=4/r^2
(1+r)/r(1-r)=4/r^2 cancle r both side
1+r/1-r=4/r
cross multiply
r+r^2=4-4r
r^2+4r+r-4=0
r^2+5r-4=0
r^2+4r+r-4=0
solve it for r factor it...
</span>
Then mark it down by less then 1%, of by whatever the number would be.