Q 11-04-125JEE MainJEE Main 2023 (8 Apr, Shift 1)Easy
At any instant the velocity of a particle of mass $500$ g is $\left(2t\hat i+3t^2\hat j\right)\ \text{m s}^{-1}$. If the force acting on the particle at $t=1$ s is $\left(\hat i+x\hat j\right)$ N, then the value of $x$ will be
Answer: (A) 3
$\vec a=2\hat i+6t\hat j$; at $t=1$, $\vec F=0.5(2\hat i+6\hat j)=\hat i+3\hat j$. So $x=3$.
Solution by Sreeraj P, M.Sc Physics