A body of mass 2 kg is projected from the ground with a velocity 20 ms−1 at an angle 30°C with the vertical. If t1 is the time in seconds at which the body is projected and t2 is the time in seconds at which it reaches the ground, the change in momentum in kg ms–1 during the time (t2- t1) is
1) 40
2) 40√3
3) 50√3
4) 60
