Dynamics Homework! An aircraft lands and deploys a drag parachute. This causes an acceleration on the plane of a=-Zv^2?

An aircraft lands and deploys a drag parachute. This causes an acceleration on the plane of
a= -Z v^2
(Z=0.0045 is a constant given below and v is instantaneous velocity)
You are required to calculate
The time required for the aircraft to slow from 80 to 5 m/s.
The distance covered during this change in velocity

For part i) use the fact that a= dv/dt

Equate this to the expression for acceleration (1 mark), separate variables, (2 marks) integrate between appropriate limits (4 marks) to obtain an expression for t , the time.(1 mark). Solve (2 marks)
For part ii) use the fact that a= dv/dt = dv/ds ds/dt =v dv/ds
Again integrate between appropriate limits to obtain an expression for s , the distance travelled