Which of the following must be known in order to determine the power output of an automobile?

$A$ body of mass $1 \ kg$ begins to move under the action of a time-dependent force $\vec{F} = (t \hat{i} + 2t^2 \hat{j}) \ N$,where $\hat{i}$ and $\hat{j}$ are unit vectors along $x$ and $y$ axes. The power developed by the above force at time $t = 3 \ s$ will be: (in $W$)

$A$ body of mass $2 \text{ kg}$ begins to move under the influence of a time-dependent force $\vec{F} = (2t\hat{i} + 6t^2\hat{j}) \text{ N}$, where $\hat{i}$ and $\hat{j}$ are unit vectors along the $x$ and $y$-axis respectively. The power produced by the force at $t = 2 \text{ s}$ is . . . . . . $\text{W}$.

$A$ body at rest is moved along a horizontal straight line by a machine delivering a constant power. The distance moved by the body in time $t$ is proportional to :

$A$ car of mass $m$ is driven with constant power $P$. If it starts from rest,find its velocity $v$ after traveling a distance $x$.

$A$ train of mass $10^6 \ kg$ is moving at a constant speed of $108 \ km/h$. If the frictional force acting on it is $0.5 \ N$ per $100 \ kg$,then the power of the train is (in $kW$)