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,

\((c)\) during the entire 3.0-s interval?