What is dynamics?

$A$ particle of mass $m$ at rest is acted upon by a force $P$ for a time $t$. Its kinetic energy after an interval $t$ is

$A$ 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 $s$)

$A$ force of $100 \, dynes$ acts on a mass of $5 \, g$ for $10 \, s$. The velocity produced is ......... $cm/s$.

$A$ body of mass $10 \,kg$ is acted upon by a force given by the equation $F = (3t^2 - 30) \,N$. The initial velocity of the body is $10 \,m/s$. What is the velocity of the body after $5 \,s$ (in $\,m/s$)?

The motion of a particle of mass $m$ is described by $y = ut + \frac{1}{2}gt^2$. Find the force acting on the particle.