A projectile of mass m is shot straight up with initial

Question

Solve the all parts of following question:

Question: A projectile of mass m is shot straight up with initial velocity vo and feels a quadratic air resistance force of the form F =-kv², where k=mg/u². (k and u are constants and g is the acceleration of gravity.)

Part A: Find the speed of the projectile at time t while the projectile is still moving upwards. (Hint: you will need to know or calculate an indefinite integral and apply initial conditions.)

Part B: Take the limit u approaches infinity (that is, k approaches 0) in the above expression and show that it goes over to the standard expression for resistance-free vertical motion.

Part C: Find the time T at which the projectile reaches its maximum height. (Hint: the result will be of the form of a constant multiplying the tangent of another constant.)

I want you to clarify the physics in this above question.