Define average power.

$A$ lamp consumes $1000\, J$ of electrical energy in $10\, s$. What is its power (in $, W$)?

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

$A$ certain household has consumed $250$ units of energy during a month. How much energy is this in joules?

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.

Calculate the work required to be done to stop a car of $1500 \, kg$ moving at a velocity of $60 \, km/h$. (in $J$)