1.A projectile is fired at speed $u=20\text{ m/s}$ at an angle $30^\circ$ above horizontal. Find maximum height, time of flight, and horizontal range.
2.A particle moves in a circle of radius $r=5\text{ m}$ at a constant speed $v=10\text{ m/s}$. Find centripetal acceleration.
3.Prove that the trajectory of a projectile is parabolic.
4.A swimmer can swim at $4\text{ km/h}$ in still water. River flows at $3\text{ km/h}$. In what direction should the swimmer head to cross shortest distance?
