$A$ pair of bullocks exerts a force of $140 \, N$ on a plough. The field being ploughed is $15 \, m$ long. How much work is done in ploughing the length of the field (in $, J$)?

An object of mass $m$ is moving with a constant velocity $v$. How much work should be done on the object in order to bring the object to rest?

$A$ certain force acting on a $20 \, kg$ mass changes its velocity from $5 \, m \, s^{-1}$ to $2 \, m \, s^{-1}$. Calculate the work done by the force. (in $J$)

What is the kinetic energy of an object?

Write an expression for the kinetic energy of an object.

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.