A bomb of mass 1 kg is thrown vertically upwards with a speed of 100 m/s. After 5 seconds it explodes into two fragments. One fragment of mass 400 gm is found to go down with a speed of 25 m/s. What will happen to the second fragment just after the explosion? (g = 10 m/s) (a) It will go upward with speed 40 m/s (b) It will go upward with speed 100 m/s (c) It will go upward with speed 60 m/s (d) It will also go downward with speed 40m/s