Question

A disc is performing pure rolling on a smooth stationary surface with constant angular velocity as shown in figure. At any instant, for the lower most point of the disc -

• A. velocity is v, acceleration is zero
• B. velocity is zero, acceleration is zero
• C. velocity is v, acceleration is $v^2/R$
• D. velocity is zero, acceleration is $v^2/R$

Answer 1

Answer: (D)

velocity is zero, acceleration is $v^2/R$

Answer 2

$v _{ A }=0$ (due to pure rolling)
Angular acceleration (for A), a
$=R w^{2}=R \frac{v^{2}}{R^{2}}$
$\Rightarrow a=\frac{v^{2}}{R}$