I am doing a project on projectiles in sport and have set up the following differential equations when investigating the projectile of a golf ball with air resistance:

mx'' = -kx' and my'' = -mg -ky'

with initial conditions:

x(0)=0

x'(0)=u0=ucos(alpha)

y(0)=0

y'(0)=vo=usin(alpha)

Could someone help me solve these differential equations and show me the method in which it is done. I am really not sure how to do them.

Thanks