sequence of integral of a function

Let $a_n=\frac{1}{n}\int_{0}^{n}\frac{log(2+x)}{\sqrt{1+x}}dx$ then i want to show $\lim_{n\to\infty}a_n\rightarrow 0$.

i assume $b_n=\int_{n-1}^{n}\frac{log(2+x)}{\sqrt{1+x}}dx$ and $a_n=\frac{b_1+b_2\cdots +b_n}{n},$then $\lim_{n\to\infty}a_n= \lim_{n\to\infty}b_n$ but then unable to compute $b_n$