An object with mass $500 \ g$ moves along the $x$-axis with speed $v = 4 \sqrt{x} \ m/s$. The force acting on the object is ....... $N$.

Newton's second law gives the measure of

What is dynamics?

At any instant,the velocity of a particle of mass $500 \, g$ is $(2t \hat{i} + 3t^2 \hat{j}) \, ms^{-1}$. If the force acting on the particle at $t = 1 \, s$ is $(\hat{i} + x \hat{j}) \, N$,then the value of $x$ will be:

The linear momentum $p$ of a body of mass $5 \,kg$ varies with time $t$ as $p = 5t^2 + t + 5$. It follows that the body is moving with:

The velocity $(v)$ of a particle (under a force $F$) depends on its distance $(x)$ from the origin (with $x > 0$) as $v \propto \frac{1}{\sqrt{x}}$. Find how the magnitude of the force $(F)$ on the particle depends on $x$.