radius of a circle: diameter is 1.3 * 10^(-12)

[angels]

Ok, this is new to me, please have patience... I have a medical/health issue and have a hard time with working with numbers and memory. So please, I ask that you bare with me?

My question is:

I am given the diameter of a circle: 1.3x10^-12
I know and have worked the 10^-12 and got 1/10, 1/10,1/10,1/10,1/10,1/10,1/10,1/10,1/10,1/10,1/10,1/10 which equals 120.
So I think I would then have to multiply 1.3x120? Which gives me 156, Is this correct? but this does not makes sense to me, please help.. Would I then divide 156 by 2? that would give me 78... is this the correct answer?

 

[Loren]

Re: radius of a circle

I am given the diameter of a circle: 1.3x10^-12
I know and have worked the 10^-12 and got 1/10, 1/10,1/10,1/10,1/10,1/10,1/10,1/10,1/10,1/10,1/10,1/10 which equals 120.
So I think I would then have to multiply 1.3x120? Which gives me 156, Is this correct? but this does not makes sense to me, please help.. Would I then divide 156 by 2? that would give me 78... is this the correct answer?

Something seems to be wrong here. The notation 10^-12 means \(\displaystyle \frac{1}{10^{12}}\) which means \(\displaystyle \frac{1}{10\cdot 10\cdot 10\cdot 10\cdot 10\cdot 10\cdot 10\cdot 10\cdot 10\cdot 10\cdot 10\cdot 10}\) which is \(\displaystyle \frac{1}{1,000,000,000,000}\). Is this what is meant?

 

[angels]

I am sorry :? , I may have put this in wrong... the problem is this: diameter is 1.3 multiplied by 10 to the -12 power I am supposed to find the radius. The answer I have now is 6.5 mutliplied(X) by 10 to the -13 power. Would this be correct?

 

[wjm11]

the problem is this: diameter is 1.3 multiplied by 10 to the -12 power I am supposed to find the radius. The answer I have now is 6.5 mutliplied(X) by 10 to the -13 power. Would this be correct?

R = 6.5 x 10^(-13) is correct.