KNOW WHY BASE OF PACKAGED WATER BOTTLE IS FLAT !!

The bumps or the corrugations in the foot of the bottle increases the strength of the bottle. Take a sheet of paper and fold it. You can easily fold the paper. Now bend any one side of the sheet and try to fold it. You will now feel some resistance. Now, roll the paper into a pipe and try folding it. It will be little hard to fold the paper pipe. Bending any material increases its strength and rigidity. This is because; rolling the paper increases its moment of inertia around the bending axis.

Soft drinks are served chilled. When a liquid is cooled, its volume changes and the bottle must not buckle because of this change in volume. The corner or the tip of the bump can slightly expand/contract without breaking which takes care of the change in volume of the liquid.

Soft drink bottles have to stand up to pressure because of the carbonation. The 5 point bottoms are designed to hold the pressure better. A 5 point bottom isn't the only way, its just one way that works well and is in common use.Because bottles of carbonated liquid are pressing outward, which would cause a flat bottom to bulge out, become rounded, and then wouldn't stand up right any more -- the five points make a steady base no matter how much pressure is inside.

Bottled water is not carbonated so there is no need for a pointed bottom. A flat bottom uses less plastic, and holds up better in drop testing.

KNOW WHY I-SECTION BEAMS ARE USED FOR RAILWAY TRACKS !!

Generally rail tracks are made in I Section.We might wonder many times that why any other shape is not used.We might also wonder, why solid section is not used??We will discuss the reason behind selection of I beam for railway tracks in this article.

The usual, Flat Footed rails used for Broad Gauge lines is shown below with its components below.

This is typical shape of the cross-section of a track laid with Flat-footed Rails.

The Bull headed rails resemble the 'I' shape more correctly.

These are shaped so for following purposes:

> The top portion or the HEAD of the rail is thicker to take up the impact of the fast moving wheels, and carry the load of trains preventing abrasion of the tracks.

>The WEB of the rail is to uplift the train from the ground level; and as the inner flanges of wheels are of greater area than the outer flanges as shown below, so the web mainly provides clear cover (distance) between wheel base and the sleeper/ ballast layer.

>The FLAT FOOT provides two-fold purpose. Easy clamping i.e fixing to the sleeper beneath it because of wider area as well as greater surface area due to flat foot helps in load transfer to the sleeper more efficiently which further transfers the load to ballast and later sub-base.

WHY I-SHAPED ONLY USED,WHY NOT ANY OTHER SHAPE:

• A beam is more efficient when more material is AWAY from the center. It’s has more strength as compared to solid.

• Upper half should be wide enough to support the wheel and lower half should be wide & thick enough for clamping. Taking out extra materials saves significant amount of iron without compromising over strength thus giving it the shape of what you asked.
• Rail needs to be stiff in the vertical direction to take the load of the train.
• It needs to be relatively flexible in the horizontal direction so it can easily bend around curves.So material is reduced at the center to allow a bit of flexibility.

DIFFERENCE BETWEEN COOLANT AND LUBRICANT EXPLAINED !!

We will be talking these two terms in context to engine.

COOLANT :

Coolant in engine is used to absorb the heat of the engine. It is used in radiator and circulated outside the engine(They pass through the engine through jackets provided).

Water is used as coolant but now a days chemicals are used along with water. They prevent the rusting, cool engine fast and doesn't freeze.

LUBRICANT:

Lubricants are used inside the engine. They are hydrocarbons made up of base oil and additives. Base oil is the product of refining of crude like diesel and petrol and additives are chemicals mixed with base oil for specific purposes.

They reduce friction, seals the engines, indicates service life, clean the carbon, cool the engines, preventing breaking of parts and distributes the pressure. Lubricants outside the engine are used as greases and gear oil.