The linear density ρ in a rod 5 m long is 8/ sqrt(x + 4) kg/m, where x is measured in meters from one end of the rod. Find the average density ρave of the rod.

Question

The linear density ρ in a rod 5 m long is 8/sqrt(x+4) kg/m,

 where x is measured in meters from one end of the rod. Find the average density ρ_ave of the rod.

Answer 1

I recently answered a similar question and received a surprisingly negative comment. I will try again.

The average you are looking for is (1/5) ∫ 8 dx/sqrt(x+4) between 0 and 5.

If you cannot compute that integral, make a comment to that effect & I will try to help you further.