A) 40
B) 30
C) 25
D) 15
Correct Answer: A
Solution :
Total force, \[\overrightarrow{F}=(4\hat{i}+\hat{j}-3\hat{k})+(3\hat{i}+\hat{j}-\hat{k})\] \[\overrightarrow{F}=7\hat{i}+2\hat{j}-4\hat{k}\] The particle is displaced from \[A(\hat{i}+2\hat{j}+3\hat{k})\]to\[B(5\hat{i}+4\hat{j}+\hat{k})\] \[\therefore \]Displacement \[\overrightarrow{AB}=(5\hat{i}+4\hat{j}+\hat{k})-(\hat{i}+2\hat{j}+3\hat{k})\] \[=4\hat{i}+2\hat{j}-2\hat{k}\] Work done\[=\overset{\to }{\mathop{F}}\,.\overset{\to }{\mathop{AB}}\,\] \[(7\hat{i}+2\hat{j}-4\hat{k}).(4\hat{i}+2\hat{j}-2\hat{k})\] \[=28+4+8=40\]unit.You need to login to perform this action.
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