Question

Speed of a particle moving in a circle varies with time as, $v=2t$ . Then

• A. angle between velocity vector and acceleration vector is increasing with time
• B. $a_t$ is constant while $a_r$ is increasing with time.
• C. both A and B are correct
• D. both A and B are wrong

Answer 1

The correct option is C both A and B are correct

$a_t=\frac{dv}{dt}$. Where $a_t$ is tangential acceleration, v is speed.

$a_r=\frac{v^2}{gr}$ where $a_r$ is radial acceleration, and v is speed.

Herr $a_t=2$ which is constant, and $a_r$ is increasing as v is increasing with time so both options are correct because as $a_r$increases then net acceleration vector also bends towards $a_r$ so angle between velocity and acceleration vector increases.