WB JEE Medical WB JEE Medical Solved Paper-2006

  • question_answer
    A force-time graph for a linear motion of a body is shown in the figure. The change in linear momentum between 0 and 7 s is :

    A)  \[2\,N-s\]                          

    B)  \[3\,N-s\]

    C)   \[4\,N-s\]                         

    D)  \[5\,N-s\]

    Correct Answer: A

    Solution :

                     Since,                   \[F=\frac{\Delta p}{\Delta t}\] or                            \[\Delta p=F\Delta t\] we can say that momentum between 0 to 7 s isequal to the vector area enclosed by theforce-time graph from 0 to 7s. So, Change in linear momentum = vector area of triangle OAB+vectorarea ofsquare BCDE + vector area of triangle \[EFG+\]vector area of square \[GHIJ+\]vector area oftriangle JKL \[=\left[ \frac{1}{2}\times 1\times (-1) \right]+[2\times 2]+\left[ \frac{1}{2}\times 2\times (-2) \right]\]                                 \[+\,[1\times 1]+\left[ \frac{1}{2}\times 1\times (-1) \right]\] \[=-\frac{1}{2}+4-2+1-\frac{1}{2}=2N-s\]                              


You need to login to perform this action.
You will be redirected in 3 sec spinner