MCQ
$A$ disc of radius $R$ is rolling purely on a flat horizontal surface, with a constant angular velocity. The angle between the velocity and acceleration vectors of point $P$ is
- Azero
- ✓$45^o$
- C$135^o$
- D$tan^{-1}(1/2)$
✓
Answer
Correct option: B.
$45^o$
b
$\mathrm{a}_{\mathrm{r}}=\mathrm{R} \omega^{2}$ (radial acceleration is directed towards centre at point $\mathrm{P}$.
$\mathrm{a}_{\mathrm{r}}=\mathrm{R} \omega^{2}$ (radial acceleration is directed towards centre at point $\mathrm{P}$.
$\cos \theta=\frac{v_{c m}}{v_{p}}=\frac{v_{c m}}{\sqrt{2} v_{c m}}=\frac{1}{\sqrt{2}}$
$\theta=45^{\circ}$
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