Question

Describe an activity to show the presence of atmospheric pressure.

Answer 1

Aim:

1. To study the presence of atmospheric pressure.

Materials needed:

1. Glass tumbler
2. Two straws
3. Water

Procedure:

1. Take a straw and make holes in its upper part.
2. Fill a tumbler with drinking water.
3. Drink water from a tumbler with a normal straw(without holes in its upper part).
4. Again try to drink water from a tumbler with a straw having holes.

Observations:

1. We can drink water easily with a normal straw.
2. We are unable to drink water with a straw having holes.

Conclusion:

1. When we drink water with a normal straw, low pressure is created in the straw. Hence, water from the tumbler rushes into the straw.
2. But when we try to drink water using a straw having holes, the pressure inside the straw does not decreases and hence water does not enter the straw. Thus we cannot drink water.

Hence, atmospheric pressure exists.