The \(x\) component of a car's velocity increases from 0 to \(+5.0 \mathrm{~m} / \mathrm{s}\) in \(1.0 \mathrm{~s}\), and then from \(+5.0 \mathrm{~m} / \mathrm{s}\) to \(+10 \mathrm{~m} / \mathrm{s}\) in the next \(2.0 \mathrm{~s}\). What is the \(x\) component of its average acceleration

(a) during the first second,

(b) during the last 2 seconds, and

(c) during the entire 3.0-s interval?