Axe, nail, knife, injection needle, bullet.

Honey. Honey flows slower than oil. So it has greater viscosity.

i) The pressure exerted by the mercury column in a barometer is considered as the pressure of magnitude 'one atmosphere'.
ii) 1 atm = pressure due to 76 cm of mercury column in a barometer = 1.01 x 10⁵ Nm^-2.

Friction is produced due to the geometrical dissimilarities of the surface of the bodies, which are in relative motion.

i) When force is exerted on raw rice, it gets grind to form rice flour
ii) When force is exerted on an inflated balloon at different angles, the shape of the balloon gets changed.

i. Camel have large padded feet, which increase the area of contact with the sandy ground.
ii. This reduces the pressure and walk easily on sand.

Pascal's law states that the pressure applied at any point of a liquid at rest, in a closed system will be distributed equally through all directions of the liquid.
Applications of Pascal's law:
i) In an automobile service stations, the vehicles are lifted upward using the hydraulic lift, which works as per Pascal's law.
ii) Automobile brake system works according to Pascal's law.
iii) The hydraulic press is used to make the compressed bundles of cloth or cotton so as to occupy less space.

Frictional force arises when two or more bodies in contact move or tend to move, relative to each other. It acts always in the opposite direction of the moving body.
Examples:
(i) To light a matchstick.
(ii) To stitch a cloth in a sewing machine.

Experiment:
i) Take a plasitc bottle
ii) Punch three holes on its side in the same direction but at different heights.
iii) Now pour some water into it and let it flow through the holes.
iv) Observe the flow of water.
Inference:
i) The water comes out from all the holes with a different force and falls on the table at points that are at variable distance from the bottle.
ii) Water from the lowest hole comes out with the greatest force and falls at a point that is at the maximum distance from the bottle.
iii) Water from the top most hole comes out with the least force and Falls at the point that is at the minimum distance from the bottle.
Result;
This activity confirms that the pressure in a liquid varies with the depth of the point of observation in it.

Types of Friction:
Friction can be classifed into two basic types
I Static friction
II. Kinetic friction
I. Static friction:
The friction experienced by the bodies which are at rest is called static friction.
eg:- a knot in a thread.
II. Kinetic friction:
Friction existing during the motion of bodies is called kinetic friction
Kinetic friction can be classified into two types
(i) Sliding friction
(ii) Rolling friction
(i) Sliding friction:
When a body slides over the surface of another body, the friction acting between the surfaces in contact is called sliding friction
eg: Sliding on snow in a sled.
(ii) Rolling friction:
When a body rolls over another surface, the friction acting between the surfaces in contact is called rolling friction.
eg: Wheels in vehicles, trolleys, Suitcases.

While travelling in an aeroplane atmospheric pressure decreases with increasing altitude. So pressure inside the aeroplane can also decreases. The pressure inside the fountain pen is more compared to its surrounding Due to varying pressure, the ink gets spilled. Due to ink spillage, fountain pens are not advisable to use while travelling in an aeroplane.