21 An antiaircraft shell is fired vertically upward with a muzzle velocity of 1000 ms-¹. Calculate the maximum height it can attain, the time taken to reach this height, the instantaneous velocities at the ends of 20 sec and 50 sec. d. When will its height be 37.5 km? Interprete your result. Neglect air resistance. a. b. C.
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