2. Sample Papers
  3. JEE Main & Advanced

JEE Main & Advanced Sample Paper JEE Main Sample Paper-16

  • question_answer
    Forces of magnitude 3 and 4 units act along \[6\hat{i}+2\hat{j}+3\hat{k}\] and \[3\hat{i}-2\hat{j}+6\hat{k}\] respectively on a particle and displaces it from (2, 2, -1) to (4, 3,  1), then the work done is

    A)  \[\frac{124}{7}\]                             

    B) \[\frac{120}{7}\]

    C) \[\frac{115}{7}\]                                              

    D)  None

    Correct Answer: A

    Solution :

    Total force \[\overrightarrow{F}=3\left( \frac{6\hat{i}+2\hat{j}+3\hat{k}}{7} \right)+4\left( \frac{3\hat{i}-2\hat{j}+6\hat{k}}{7} \right)\] \[=\frac{1}{7}\left( 30\hat{i}-2\hat{j}+33\hat{k} \right)\] displacement\[\overrightarrow{d}=2\hat{i}+\hat{j}+2\hat{k},\] \[W=\overrightarrow{F}\cdot \overrightarrow{d}=\frac{124}{7}\]


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