Rotation 5 Question 4
13. Two identical discs of same radius $R$ are rotating about their axes in opposite directions with the same constant angular speed $\omega$. The discs are in the same horizontal plane.
At time $t=0$, the points $P$ and $Q$ are facing each other as shown in the figure. The relative speed between the two points $P$ and $Q$ is $v _r$. In one time period $(T)$ of rotation of the discs, $v _r$ as a function of time is best represented by (2012) (a)
(c)
(b)
(d)
Show Answer
Answer:
Correct Answer: 13. (a)
Solution:
- Language of question is wrong because relative speed is not the correct word. Relative speed between two is always zero. The correct word is magnitude of relative velocity.
Corresponding to above values, the correct graph is (a).
