$A$ block of mass $10\, kg$ accelerates uniformly from rest to a speed of $2\, m/s$ in $20\, s$. The average power developed in the time interval of $0$ to $20\, s$ is .............. $W$.

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

Calculate the power of a crane in watts,which lifts a mass of $100 \, kg$ to a height of $10 \, m$ in $20 \, s$. (in $, W$)

$A$ body of mass $2\, kg$ is driven by an engine delivering a constant power $1\, J/s$. The body starts from rest and moves in a straight line. After $9$ seconds,the body has moved a distance (in $m$):

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

If $\overrightarrow{F} = (60 \hat{i} + 15 \hat{j} - 3 \hat{k}) \; N$ and $\overrightarrow{V} = (2 \hat{i} - 4 \hat{j} + 5 \hat{k}) \; m/s$,then the instantaneous power is: (in $; W$)