A projectile is projected at an angle of 600  with the horizontal with speed of 10 m/s. The minimum radius of curvature of the trajectory described by the projectile is

The radius of curvature is minimum at the highest point where the centripetal force = mg And speed V = u cos αNow mV2ρ=mg⇒ucosα2ρ=g ⇒ρ=u2cos2α/g ⇒  ρmin = ucosα2g  = 10cos60029.8  m=2.55  m.