Question

Give two examples of fast changes.

Answer 1

Hint: Fast changes are those which occur within a few seconds. Some changes even occur in a fraction of seconds. In our day to day life, we come across many fast changes. Chemical reactions also have many fast reactions.

Complete step by step answer: We know that there are fast changes and slow changes. Fast changes occur within a few seconds. Some very fast changes even in a fraction of second. Such changes are hard to notice. Unless we experiment specifically for our observation. Slow changes may generally take from few minutes to few days (even years) to complete. Some slow changes can be noticed by continuous observation but some extremely slow changes are hard to notice.
In our day to day life, we see many fast and slow changes. Now we will discuss fast changes.
1. All the electronic appliances are activated at the moment we turn on the switch. This change is very fast. It occurs within a fraction of a second. This change is hard to notice. This change is almost instantaneous.
2. Spread of a gas from a container when it is left open in a room of large volume. As soon as you leave the gas in the container it spreads all over the room.

Note: Some changes like the passing of light through the room are extremely fast and impossible to notice them under normal conditions. Electron velocity in current wires is very less but due to the vast number of carriers spread all over the wire activation of electronic appliances is fast changing.