Question

Find the moduli of the angular velocity at the moment $t=10.0s$.

• A. $4rad/s$
• B. $8rad/s$
• C. $5rad/s$
• D. $10rad/s$

Answer 1

Answer: (B)

$8rad/s$

Angular velocity$\omega =at\overrightarrow{i}+b{t}^2\overrightarrow{j}$ $a=0.5b=0.06t=10$
$\overrightarrow{\omega }=0.5t\overrightarrow{i}+0.06t^2\overrightarrow{j}$
$\overrightarrow{\omega }=0.5\times 10\overrightarrow{i}+0.06(10{)}^2\overrightarrow{j}$
$\overrightarrow{\omega }=5\overrightarrow{i}+6\overrightarrow{j}$
$\omega =\sqrt{5^2+6^2}$
$\omega =\sqrt{61}\approx 8$