NEET Sample Paper NEET Sample Test Paper-39

  • question_answer A particle starts its motion from rest under the   action of a constant force. If the distance covered in first 10 s is \[{{s}_{1}}\]and that covered in the first 20 s is \[{{s}_{2}},\]then

    A) \[{{s}_{2}}=2{{s}_{1}}\]

    B) \[{{s}_{2}}=3{{s}_{1}}\]

    C) \[{{s}_{2}}=4{{s}_{1}}\]

    D) \[{{s}_{2}}={{s}_{1}}\] 

    Correct Answer: C

    Solution :

     If the particle is moving in a straight line under the action of a constant force or under constant acceleration [a] Using, \[s=ut+\frac{1}{2}a{{t}^{2}}.\] Since the body starts from the rest\[u=0\] \[\therefore \] \[s=\frac{1}{2}a{{t}^{2}}\] Now, \[{{s}_{1}}=\frac{1}{2}a{{(10)}^{2}}\] ?(i) and \[{{s}_{2}}=\frac{1}{2}a{{(20)}^{2}}\] ?(ii) Dividing Eq. (i) and Eq. (ii), we get \[\frac{{{s}_{1}}}{{{s}_{2}}}=\frac{{{(10)}^{2}}}{{{(20)}^{2}}}\Rightarrow {{s}_{2}}=4{{s}_{1}}\]


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