Value of dot product

There are two random vectors $\mathbf{a}=[a_1,a_2]$ and $\mathbf{b}=[b_1,b_2]$. Let $s$ be the dot product of these two vectors, that is $s=\mathbf{a}\cdot \mathbf{b}=a_1{b}_1+a_2{b}_2$.

Assume $a_1$, $a_2$, $b_1$, $b_2$ are mutually independent random variables of the uniform distribution on the interval [0, 2]. Find the probability of value $s$ less than 5 and the expected value of $s$. Give your answer rounded to 8 digits after the decimal point.

Answer format: [probability],[expected value]
(Sample input: 0.12345678,1.23456789)

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Thanks to baihacker for the idea.