Science 3

Day 3

Power Line, having pulley

Use this to load the system to pull

The fog

Clouds at a lower altitude

Cold air sinks at night, in the day the cloud slowly moves up

Eiffel Tower Lighthouse

Might use convex mirror, lens is not possible as it might crack

Intensity of light will drop as mirror gets thicker

  

The Ever Lasting Fire

Different chemicals have different Chemical Potential Energy leading to different temperatures of combustion

The pressure at the tunnel when a train rushes through 

When a train enters a tunnel, it compresses the air in front of it like a piston. Unlike outside air, air in a tunnel can't be simply pushed aside—the tunnel walls are in the way.

Some of the air is pushed forward, all the way down to the tunnel's other end, but most of it rushes through the narrow space between the train and the tunnel walls, filling in the area behind the train.

Being forced into this narrow space makes the air rush faster, exactly as water speeds up at the base of a funnel. In fact, this tunnel air can rush backward much faster than the train's forward speed!

This fast-moving air creates a kind of suction on the train, increasing the air pressure outside, lowering the air pressure inside and making your ears go "pop".

Airplane Pressure 

"In most airliners, the air is compressed by the engines, cooled by the air conditioning system and then sent to the cabin. Fresh air can also be routed to the cabin from a small jet engine in the back of the airplane, known as an auxiliary power unit. 

HSR vs Metro speeds

Metro will accelerate and decelerate quickly

But HSR will accelerate and decelerate at a slower rate due to its long distance. 

Different types of Lifts http://www.meyer.com.sg/lifts.aspx

a. Counterweight lift https://www.explainthatstuff.com/how-elevators-work.html
b. Hydraulic lift (takes very long) https://elevation.fandom.com/wiki/Hydraulic_elevators  

c.  Maglev Lifts: https://www.google.com/amp/s/thesuffolkblog.com/2015/12/02/update-maglev-elevator-prototype-moves-mankind-closer-to-mile-high-buildings/amp/