A 
length of steel wire and a 
length of brass wire are joined together. The combined wires are suspended from a fixed support and a force of 
is applied, as shown.
The Young modulus of steel is 
. The Young modulus of brass is 
. Each wire has a cross-sectional area of 
. The wires obey Hooke’s law. What is the total extension? Ignore the weights of the wires.
