Question

there is a groove which is in a cylindrical form and is made in a cylindrical piece of wood of length 17.5cm. The groove is filled with graphite and the cylindrical graphite block is of same length as that of wooden piece. If the diameter of the graphite cylinder is 3mm and outer diameter of the wooden cylinder is 10mm. find the volume of the wood and volume of the graphite used

Answer 1

Vol of cylinder\( = 2\pi r^2h\)

Answer 2

pi r^2h= vol of cylinder

Answer 3

right.. no "2"

Answer 4

so, what seems to be the problem here?