Cylinder help please?

Question

It has a diameter of 0.005m and a length of 0.084m. The diameter is then shortened to 0.0025m and i need to get the new length but im stuck, will the volumes be the same?

 

Answer 1

Volume of the cylinder,V=πr^2h

                                           =πd^2h/4

Volume are equal in given two conditions

V1=V2

πd1^2h1/4=πd2^2h2/4

d1^2h1=d2^2h2

Substitute 0.005 m for d1,0.0025 m for d2 and 0.084 m for h1.

0.005^2*0.084=0.0025^2*h2

h2=0.336 m