$A$ body of mass $5 \ kg$ starts from the origin with an initial velocity $(30 \hat{i} + 40 \hat{j}) \ m/s$. If a constant force $-(\hat{i} + 5 \hat{j}) \ N$ acts on the body,then the time in which the $y$-component of its velocity becomes zero is (in $s$)

What is dynamics?

An object with a mass of $10\, kg$ moves at a constant velocity of $10\, m/s$. $A$ constant force then acts for $4\, s$ on the object and gives it a speed of $2\, m/s$ in the opposite direction. The force acting on the object is ......... $N$.

$A$ particle of mass $2/3 \, kg$ with velocity $v = -15 \, m/s$ at $t = -2 \, s$ is acted upon by a force $F = k - \beta t^2$. Here,$k = 8 \, N$ and $\beta = 2 \, N/s^2$. The motion is one-dimensional. Then,the speed at which the particle acceleration is zero again,is ........... $m/s$.

$A$ particle of mass $m$ is at rest at the origin at time $t = 0$. It is subjected to a force $F(t) = F_0e^{-bt}$ in the $x$-direction. Its speed $v(t)$ is depicted by which of the following curves?

The engine of a car produces an acceleration of $4\,m/s^2$ in the car. If this car pulls another car of the same mass,what will be the acceleration produced in $m/s^2$?