2 A particle is projected vertically upwards from horizontal ground. The speed of the particle 2 seconds after it is projected is \(5 \mathrm {~m} \mathrm {~s} ^ { - 1 }\) and it is travelling downwards.

1. Find the speed of projection of the particle.
2. Find the distance travelled by the particle between the two times at which its speed is \(10 \mathrm {~m} \mathrm {~s} ^ { - 1 }\).