MCQ
A particle moves with a constant velocity parallel to the X-axis. Its angular momentum with respect to the origin:
- AIs zero.
- BRemains constant.
- ✓Goes on Increasing.
- DGoes on decreasing.
✓
Answer
Correct option: C.
Goes on Increasing.
Explanation:
For angular momentum. we have:
$\overrightarrow{\text{L}}=\text{m}\Big(\overrightarrow{\text{r}}\times\overrightarrow{\text{v}}\Big)$
$\overrightarrow{\text{v}}=\text{v}\hat{\text{i}}$ and $\overrightarrow{\text{r}}=\text{x}\hat{\text{i}}+\text{y}\hat{\text{j}}$
So, $\overrightarrow{\text{L}}=-\text{mvy}\hat{\text{k}}$
m, v and y are constant; therefore, angular momentum remains constant.
For angular momentum. we have:
$\overrightarrow{\text{L}}=\text{m}\Big(\overrightarrow{\text{r}}\times\overrightarrow{\text{v}}\Big)$
$\overrightarrow{\text{v}}=\text{v}\hat{\text{i}}$ and $\overrightarrow{\text{r}}=\text{x}\hat{\text{i}}+\text{y}\hat{\text{j}}$
So, $\overrightarrow{\text{L}}=-\text{mvy}\hat{\text{k}}$
m, v and y are constant; therefore, angular momentum remains constant.
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