Define $1$ watt of power.

Write an expression for the kinetic energy of an object.

Write an expression for the work done when a force is acting on an object in the direction of its displacement.

Can there be displacement of an object in the absence of any force acting on it?

$A$ force of $7\, N$ acts on an object. The displacement is $8\, m$ in the direction of the force. What is the work done in this case (in $, J$)?

Look at the activities listed below. Reason out whether or not work is done in the light of your understanding of the term 'work'.
$1$. Suma is swimming in a pond.
$2$. $A$ donkey is carrying a load on its back.
$3$. $A$ windmill is lifting water from a well.
$4$. $A$ green plant is carrying out photosynthesis.
$5$. An engine is pulling a train.
$6$. Food grains are getting dried in the sun.
$7$. $A$ sailboat is moving due to wind energy.