Question

A body is moving is x-y plane as shown in a circular path of radius 2 m. At a certain instant when the body is crossing the positive y-axis its acceleration is $(6\widehat{i} - 8\widehat{j})$ m/s². Then its angular acceleration and angular velocity at this instant will be –

• A. – $3\widehat{k}$ rad/s² and $- 2\widehat{k}$rad/s respectively
• B. +$3\widehat{k}$rad/s² and $+ 2\widehat{k}$rad/s respectively
• C. –$4\widehat{k}$rad/s² and $- \sqrt{3}\widehat{k}$rad/s respectively
• D. $+ 4\widehat{k}$rad/s² and $+ \sqrt{3}\widehat{k}$rad/s respectively

Answer 1

Answer: (A)

– $3\widehat{k}$ rad/s² and $- 2\widehat{k}$rad/s respectively

Answer 2

$\overrightarrow{a} = 6\widehat{i} - 8\widehat{j}$

\ a_r = 8 and a_t = 6

rw² = 8 and ra = 6