In: Math
You plan to calculate the volume of a tall, thin cylinder from measurements of its radius and height. Which dimension should you measure more carefully? Give reasons for your answer.
The volume of the cylinder with radius "r" and height "h" is given by

If the error in height is   
then

Similarly if the error in radius be 

Then the error in its volume


  

Since the product of   
are smal we can ignore them

Dividing both sids by   
  

Hence the maximum relative error in volume

As we can see the relative error in radius contribute more to relative error in volume
So radius of the wire is to be measured more accurately to minimize the error in Volume.