A) \[-80\,\hat{k}\]
B) \[(10\hat{i}-16\hat{j})\]
C) \[-40\,\hat{k}\]
D) \[40\hat{k}\]
Correct Answer: A
Solution :
[a] Angular momentum L\[=m(\overrightarrow{r}\times \overrightarrow{v})\] \[=2kg\left( \overrightarrow{r}\times \frac{d\overrightarrow{r}}{dt} \right)=2kg(5\hat{i}-2{{t}^{2}}\hat{j})\times (-4\,t\hat{j})\] \[=2kg(-20\,t\,\hat{k})=2\,kg\times -20\times 2\,{{m}^{-2}}{{s}^{-1}}\hat{k}\] \[=-80\,\hat{k}\]You need to login to perform this action.
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