FORCE & PRESSURE PART 5 {THE LAST}

žThus , as per above activity , it is proved that liquids at the bottom of the container depends on the height of its column .

žIt means that pressure applied by the liquids is not same at all the depths .

žPressure applied by liquid changes with change in depth .

žThe pressure increases as we go deeper into a liquid .

žLet us do the activity to understand the topic .

ž

žLike Liquids , gases also exerts pressure on the walls of the container in which they are enclosed .

žAlso , all enclosed gases in the container exert pressure equally in all directions .

žWhen a balloon is inflated by filling air in it , air exerts pressure on the walls of the balloons .

žIf  we make a hole in it , air leaks out of the balloon .

žIf someone keep his finger in front of the hole , the gush of air moving out can be felt .

ž

žYou know that there is air all around us.

žThis envelop of air is known as the atmosphere.

ž The atmospheric air extends up to many kilometres above the surface of the earth.

ž The pressure exerted by this air is known as atmospheric pressure.

žWe know that pressure is force per unit area.

ž If we imagine a unit area and a very long cylinder standing on it filled with air, then the force of gravity on the air in this cylinder is the atmospheric pressure.

žLET US SEE THE PICTURE OF THE ACTIVITY

žWhen you press the sucker, most of the air between its cup and the surface escapes out.

ž The sucker sticks to the sur face because the pressure of atmosphere acts on it.

ž To pull the sucker off the surface, the applied force should be large enough to overcome the atmospheric pressure.

ž This activity might give you an idea about the magnitude of atmospheric pressure.

žBecause the pressure inside our bodies is the same as the pressure outside of our bodies.

žIf you’ve ever gone up or down a tall mountain, or flown in an airplane at altitude, you’ve probably heard a popping, crackling sound in your ears at some point.

žThat is the sound of the pressure inside your body matching the pressure outside of your body.

žIf the pressures differ too greatly, we can be injured, usually soft parts first, like eardrums.

ž

ž Force could be a push or a pull.

ž  A force arises due to the interaction between two objects.

ž Force has magnitude as well as direction.

ž A change in the speed of an object or the direction of its motion or both implies a change in its state of motion.

ž Force acting on an object may cause a change in its state of motion or a change in its shape.

ž  A force can act on an object with or without being in contact with it.

ž  Force per unit area is called pressure.

žLiquids and gases exert pressure on the walls of their containers.

žThe pressure exerted by air around us is known as atmospheric pressure.

SO, WITH THIS OUR CHAPTER HAS ENDED

SEE U WITH NEW CHAPTER NEXT TIME BYE BYE