Rotation 3 Question 3
9. A small object of uniform density rolls up a curved surface with an initial velocity $v$. It reaches up to a maximum height of $\frac{3 v^{2}}{4 g}$ with respect to the initial position. The object is
$(2007,3$ M)
(a) ring
(c) hollow sphere
(b) solid sphere
(d) disc
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Answer:
Correct Answer: 9. (d)
Solution:
- $\quad \frac{1}{2} m v^{2}+\frac{1}{2} I \frac{v}{R}^{2}=m g \frac{3 v^{2}}{4 g}$
$$ \therefore \quad I=\frac{1}{2} m R^{2} $$
$\therefore$ Body is disc.
