2. Solved Papers
  3. Punjab Medical

Punjab Medical Punjab - MET Solved Paper-2003

  • question_answer
    A particle moves from position\[{{\overset{\to }{\mathop{r}}\,}_{1}}=3\mathbf{\hat{i}}+2\widehat{\mathbf{j}}-6\widehat{\mathbf{k}}\]to position\[\overset{\to }{\mathop{{{r}_{2}}}}\,=14\widehat{\mathbf{i}}+13\widehat{\mathbf{j}}+9\widehat{\mathbf{k}}\]under action of force\[\overset{\to }{\mathop{\mathbf{F}}}\,=4\widehat{\mathbf{i}}+\widehat{\mathbf{j}}+3\widehat{\mathbf{k}}\,\,N\]. The work done will be:

    A) \[100\,\,\text{J}\]                           

    B) \[50\,\,\text{J}\]

    C) \[200\,\,\text{J}\]                           

    D) \[75\,\,\text{J}\]

    Correct Answer: A

    Solution :

    Using the formula for work done                 \[W=\overset{\to }{\mathop{\mathbf{F}}}\,\cdot \overset{\to }{\mathop{\mathbf{r}}}\,=\overset{\to }{\mathop{\mathbf{F}}}\,\cdot (\overset{\to }{\mathop{{{\mathbf{r}}_{2}}}}\,-\overset{\to }{\mathop{{{\mathbf{r}}_{1}}}}\,)\] \[W=(4\mathbf{\hat{i}}+\mathbf{\hat{j}}+3\mathbf{\hat{k}})\cdot (14\mathbf{\hat{i}}+13\mathbf{\hat{j}}+9\mathbf{\hat{k}}\]  \[-3\mathbf{\hat{i}}-2\mathbf{\hat{j}}+6\mathbf{\hat{k}})\] \[W=(4\widehat{\mathbf{i}}+\widehat{\mathbf{j}}+3\widehat{\mathbf{k}})\cdot (11\widehat{\mathbf{i}}+11\widehat{\mathbf{j}}+15\widehat{\mathbf{k}})\]                 \[W=44+11+45=100\,\,joule\]


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