(c) Kinetic energy at highest point $(KE)_{H} = \frac{1}{2}mv^{2}\cos 2\theta$ $= K\cos^{2}\theta$ $= K({\cos{60{^\circ})}}^{2}$ $= \frac{K}{4}$
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.