Calculating Length, Diameter and Volume Change of a Laser Rod

[Knfoster]

Homework Statement

The active element of a certain laser is an ordinary glass rod 18.7 cm long and 1.33 cm in diameter. If the temperature of the rod increases by 78.5oC, calculate its increase in length. Calculate its increase in diameter. Calculate its increase in volume.

Homework Equations

change in L=Li*alfa*change in T

The Attempt at a Solution

Length increased by 0.0132 cm
Diameter increased by 9.396E-4cm
I don't know how to get the increase in volume. Could someone please help? Thanks!

 

[hage567]

You can calculate the intial volume easily enough. Look up volume expansion in your book. It should be in there. You can also look at http://hyperphysics.phy-astr.gsu.edu/hbase/thermo/thexp2.html#c3