6 A \(\boldsymbol { p }\) rticle \(P \mathrm {~m}\) s ira straitg lie . Tb ± lo ity \(v \mathrm {~ms} ^ { - 1 }\) at time \(t \mathrm {~s}\) is g ஓ ity $$\begin{array} { l l } v = 5 t ( t - 2 & \text { fo } 0 \leqslant t \leqslant 4
v = k & \text { fo } 4 \leqslant t \leqslant 4
v = 82 \quad t & \text { fo } 4 \leqslant t \leqslant \Omega \end{array}$$ wh re \(k\) is a co tan.

1. Fid \(k\).
2. Sk tcht b lo ity ime g aff \(\mathbf { 0 } \quad 0 \leqslant t \leqslant 0\)
3. Fid bet \(\mathbf { 6 }\) le \(\mathrm { s } \mathbf { 6 } t\) fo wh cht b acceleratio \(P\) is \(\mathbf { p }\) itie .
4. Fid \(\mathbf { b }\) to ald stan e trac lledy \(P\) irt \(\mathbf { b }\) in era \(10 \leqslant t \leqslant 0\)