A body rises vertically up to a height of 125 m and comes back at the point of projection in 5 s. The average speed of the body was

 

  •  A body rises vertically up to a height of 125 m and comes back at the point of projection in 5 s. The average speed of the body was 
    1. 25 m/s,
    2. 50 m/s,
    3. Zero
    4. None of these
        Ans.    As we know that speed = distance traveled / time taken,
                    Here, as the speed is changing continuously,
                    Average speed = total distance traveled / total time taken
                                            = (125 m + 125 m) / 5 s,
                                            = 250 m / 5 s
                                            = 50 m/s
                    Therefore, average speed is 50 m/s and option 2. 50 m/s is correct.

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