The acceleration of a particle is defined by the relationship a=-kx^-2 ft/s^2, where x is in feet and k is a constant. At x(0)=0.1ft, v(0)=0 and at x(1)=1ft, v(1)=10ft/s. Find the velocity at x=5ft. After I found the constant k I'm left over with a t variable in the velocity equation leaving me unable to isolate v.