KVPY Sample Paper KVPY Stream-SX Model Paper-5

  • question_answer
    A particle is projected form the ground with an initial velocity of 20 m/s at an angle of \[30{}^\circ \]with horizontal. The magnitude of change in velocity in a time interval from t = 0 to t = 0.5 s is \[(g=10m/{{s}^{2}})\]

    A) 5 m/s

    B) 2.5 m/s

    C) 2 m/s               

    D) 4 m/s

    Correct Answer: A

    Solution :

    [A] During motion force acting on particle only in downward direction i.e. mg so only its vertical velocity change during the motion \[a=\frac{mg}{m}=g\,\,downward\] \[{{v}_{y}}={{u}_{y}}+gt\] \[{{v}_{y}}-{{u}_{y}}=gt\] \[\Delta v=gt=10\times 0.5=5m/\sec \]                

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