Question

A disc rotates about its axis with a constant angular acceleration of$4\frac{rad}{s^2}.$Radial acceleration of a particle at a distance of$1cm$from the axis at the end of$1sec$is.

• A. $16\frac{cm}{s^2}$
• B. $1.6\frac{cm}{s^2}$
• C. $16\frac{m}{s^2}$
• D. $1.6\frac{m}{s^2}$

Answer 1

The correct option is A $16\frac{cm}{s^2}$

$t$ = 1 sec, $r$ = 1 cm = 0.01 m

$\alpha$ = 4 $\frac{rd}{s^2}$

Therefore angular velocity at t= 1 second,
$\omega$ = $\alpha t$ = 4 $\frac{rad}{s}$

Therefore radial acceleration,

$a_c$ = ${\omega }^{2}r$ = 0.16 $\frac{m}{s^2}$ = 16 $\frac{cm}{s^2}$