Two wires of equal length and cross sectional area suspended as shown in

Their Young's modulii are `Y_1 = 2xx10^(11)` Pa and `Y_2 = 0.90 xx 10^(11)` Pa respectively. What will be the equivalent Young's modulus of combination?

Answer

`1.45 xx 10^(11) Pa`

Explanation

The spring constant of a wire is given by `k = (F)/(Delta l) = (YA)/(l)`
Refer to

`K_(eq) = k_1 + k_2`
or `(Y2A)/(l) = (Y_1A)/(l) + (Y_2A)/(l)`
`or Y = (Y_1 +Y_2)/(2) = 2xx10^(11) + (0.90 xx 10^(11))/(2)`
` =1.45 xx 10^(11)Pa`