$A$ particle of mass $m=1 \ kg$ moves in the $xy$-plane. The force on it at time $t$ is $F(t)=[2 \sin (\alpha t) \hat{i}+3 \cos (\alpha t) \hat{j}] \ N$,where $\alpha=1 \ s^{-1}$. At time $t=0$,the particle is at rest at the origin. Calculate the magnitude of its position vector $r$ (in $m$) and velocity vector $v$ (in $m/s$) at time $t=\frac{\pi}{2} \ s$.

  • A
    $r=\frac{\pi}{2}\sqrt{13}, v=\sqrt{13}$
  • B
    $r=\sqrt{13}, v=\sqrt{9}$
  • C
    $r=\sqrt{3}, v=\sqrt{2}$
  • D
    None of these

Explore More

Similar Questions

$A$ force of $mg$ is applied to block $B$ to keep the system in equilibrium. Find the value of $T_1$.

Work done by frictional force is:

$A$ bullet of mass $0.1\,kg$ moving horizontally with speed $400\,m/s$ hits a wooden block of mass $3.9\,kg$ kept on a horizontal rough surface. The bullet gets embedded into the block and moves $20\,m$ before coming to rest. The coefficient of friction between the block and the surface is $........$ (Given $g=10\,m/s^2$)

$A$ block $B$,lying on a table,has weight $w$. The coefficient of static friction between the block and the table is $\mu$. Assume that the cord between $B$ and the knot is horizontal. The maximum weight of the block $A$ for which the system will be stationary is

At time $t=0$,a force $F=\alpha t$,where $t$ is time in seconds,is applied to a body of mass $1 \text{ kg}$,resting on a smooth horizontal plane. If the direction of the force makes an angle of $45^{\circ}$ with the horizontal,then the velocity of the body at the moment of its breaking off the plane is

Vedclass Products

For Students

Vedclass Test Series

Mock tests in real JEE/NEET style with performance analysis. 5-day free trial.

Start Free Trial
For Teachers

Exam Paper Generator

Generate Set A/B/C/D exam papers from 7.5L+ questions in 2 minutes. 3 chapters free.

Try Free
For Institutes

Online Exam Module

Live online exams with unlimited students, 360° analytics & white-label branding.

See Demo