1. A bird leaves its nest at time \(t = 0\) for a short flight along a straight line.

The bird then returns to its nest.
The bird is modelled as a particle moving in a straight horizontal line.
The distance, \(s\) metres, of the bird from its nest at time \(t\) seconds is given by $$s = \frac { 1 } { 10 } \left( t ^ { 4 } - 20 t ^ { 3 } + 100 t ^ { 2 } \right) , \quad \text { where } 0 \leqslant t \leqslant 10$$

1. Explain the restriction, \(0 \leqslant t \leqslant 10\)
2. Find the distance of the bird from the nest when the bird first comes to instantaneous rest.