Bernoulli's principle of laminar/lamellar air flow, I think. High flow speed = low pressure, low flow speed = high pressure I think. So, the wings/aerofoils are designed to induce a low pressure on the top side of the wing and a high pressure on the underside of the wing, thus producing an "aerodynamic upthrust" (a static upthrust comes from an object in water via Archimedes) and LIFT.
Two "particles" of air one going topside and the other underside meet again at the end of their motion across the wing. So, top side has to travel faster than bottom side. So top side has a lower "dynamic pressure" than underside.
And all that for 5 points ????????? (If I'm right, of course ... )
Answer:
sometimes sunset could sometimes cause a pink and orange cloud
Average speed is defined as the ratio of total distance covered in total given time
here we know that total distance that man moved is
so total distance is
now here total time of the motion is
total time will be given as
now by above formula
so his average speed is 30 km/h
Answer:
We have to show surface area 
,with few conditions that is by considering Force 
and Pressure 
to be respectively.
Explanation:
The atmospheric pressure is 
on Earth's surface.
The magnitude of the force exerted on a person by the atmosphere is 
.
Now to calculate surface area we can find it from 
and re-arranging it to.
So plugging the values,
Surface area 
Hence from the above calculations we can say that surface area is 
.
So the surface area of an average person can be said to have , using the concept of pressure and force.
