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

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.

The kinetic energy of an object of mass,$m$ moving with a velocity of $5 \,m \,s^{-1}$ is $25\, J$. What will be its kinetic energy when its velocity is doubled? What will be its kinetic energy when its velocity is increased three times?

$A$ battery lights a bulb. Describe the energy changes involved in the process.

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 $J$)