Mechanical Properties of Fluids
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Question : 27
Total: 31
A plane is in level flight at constant speed and each of its two wings has an area of 25 m 2 180 km h – 1 234 k m h – 1 1 k g m – 3 )
Solution:
Here, v 1 = 180 k m h − 1 = 50 m s − 1 ,
v 2 = 234 k m h − 1 = 65 m s − 1
area of the each wing,A = 25 m 2
and density of air,r = 1 k g m – 3
According to Bernoulli’s theorem,
P 1 − P 2 =
ρ ( v 2 2 − v 1 2 )
=
( 65 2 − 50 2 )
= 862.5 N m − 2
Now, upward lift from both the wings,
F = ( P 1 – P 2 ) × 2 A
= 862.5 × 2 × 25 N
Let M be the mass of the plane. As the plane is in level flight,F = M g
or M =
=
= 4.4 × 10 3 k g
area of the each wing,
and density of air,
According to Bernoulli’s theorem,
Now, upward lift from both the wings,
Let M be the mass of the plane. As the plane is in level flight,
or
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