1. By Nitin Oke For Safe Hands Akola www.safehandsakola.org
Force & Pressure By
Nitin Oke
For Safe Hands Akola

2. Force
Force is needed to move a stationary object or to stop a moving object or to change the direction of moving object or to change the speed of object. In short to bring change in state of motion of object
Force is also needed to change the shape of object.
Force may be contact force or non contact force

3. Types of Force Force may be contact force or non contact force.
An object is taken up
Playing tug of war
Attracting iron piece by magnet
Object falling down
Weight lifter lifts the weight
An archer pulls the bow
Light glow due to electricity
Kite fly in sky
Force may be push force or pull force.

4. Information about force
Force is vector quantity
Unit of force is newton (N) or dyne or kg m/s2
The concept of force was developed by Newton
Gravitation, Muscular, Electrical, magnetic, friction, normal reaction, tension, nuclear are examples of force

5. Effect of force
Pressure: (Amount of )Force applied ( in perpendicular direction ) on unit area is called as pressure.
Unit of pressure is N/m2 or pascal ( Pa)
To increase pressure (for same force) we need to decrease the area
Knife has sharp edge
Nail has pin point

6. Effect of force
To decrease the pressure ( for same force) we need to increase area
Broad belts of school bags
Wide grips of handle
Porter using roll of cloth before placing a load on it
If pressure is same then larger the area greater the force and smaller the area smaller the force.

7. Pressure due to liquid or gas
When we enclose the liquid or gas in a container it exerts pressure on walls of container.
The pressure due to liquid is because of its weight of column and is same in all directions.
The pressure due to gas is because of its randomly moving “particles” hit the container of gas.
Equal pressure is exerted in all possible directions

8. Effects due to pressure
When liquid is enclosed in a tube (channel) it flows from end of high pressure to end of low pressure.
Flow of blood is due to pressure of heart
Drink rises through straw due to lung pressure
Tooth pest come out when we squeeze it to increase the pressure
Injection injects due to pressure.

9. Atmospheric pressure
Our surrounding is made up of gases like nitrogen 78% , oxygen 21% , carbon dioxide & Argon (0.98%) , remaining water vapor. Its weight creates force and hence pressure called as atmospheric pressure.
It is x 105N/m2
nearly 105N per sq meter.

10. Use of atmospheric pressure
It holds our body, to burst
It changes air, to wind hence rains
It allows us to use straw to drink.
Takes away the air from inflated balloon when we lose the grip.
It was responsible factor for experiment performed by Otto Van Guericke which was witnessed by great Napoleon Bonaparte.

11. By Nitin Oke For Safe Hands Akola www.safehandsakola.org
Magnetism By
Nitin Oke
For Safe Hands Akola