Q. The momentum of a particle is $\overrightarrow{P}$=2cos$t\widehat{i} + 2sint\widehat{j}$. What is the angle between the force $\overrightarrow{F}$ acting on the particle and the momentum $\overrightarrow{P}$
A) 65${^\circ}$
B) 90${^\circ}$
C) 150${^\circ}$
D) 180${^\circ}$
Explanation
(b) $\overrightarrow{F_{\ }} = \frac{d\overrightarrow{p_{\ }}}{dt} = \left( - 2\sin\ t \right)\widehat{i} + (2\cos t)\widehat{j}$
cos$\widehat{\theta} = \frac{\overrightarrow{F_{\ }} \bullet \overrightarrow{P}}{Fp}$=0
$\therefore\ \ \ \theta = 90{^\circ}$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.