5. A particle \(P\) is moving in a plane with constant acceleration. The velocity, \(\mathbf { v } \mathrm { m } \mathrm { s } ^ { - 1 }\), of \(P\) at time \(t\) seconds is given by
$$\mathbf { v } = ( 7 - 5 t ) \mathbf { i } + ( 12 t - 20 ) \mathbf { j }$$
- Find the speed of \(P\) when \(t = 2\)
- Find, to the nearest degree, the size of the angle between the direction of motion of \(P\) and the vector \(\mathbf { j }\), when \(t = 2\)
The constant acceleration of \(P\) is a m s-2
- Find \(\mathbf { a }\) in terms of \(\mathbf { i }\) and \(\mathbf { j }\)
- Find the value of \(t\) when \(P\) is moving in the direction of the vector \(( - 5 \mathbf { i } + 8 \mathbf { j } )\)