5 A particle moves such that at time \(t\) seconds its acceleration is given by
$$( 2 \cos t \mathbf { i } - 5 \sin t \mathbf { j } ) \mathrm { m } \mathrm {~s} ^ { - 2 }$$
- The mass of the particle is 6 kg . Find the magnitude of the resultant force on the particle when \(t = 0\).
- When \(t = 0\), the velocity of the particle is \(( 2 \mathbf { i } + 10 \mathbf { j } ) \mathrm { m } \mathrm { s } ^ { - 1 }\).
Find an expression for the velocity of the particle at time \(t\).