To have a surface area of 9π square units of a ball, what should be the diameter (in units) of the ball?
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The surface area of a sphere is given by the formula: 4πr², where r is the radius of the sphere.
We are given the surface area as 9π. So, set the formula equal to 9π:
4πr² = 9π
Divide both sides by π:
4r² = 9
Now, divide by 4:
r² = 9/4
Take the square root of both sides:
r = √(9/4) = 3/2 = 1.5 units.
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