Question

A plane is in level flight at constant speed and each of its two wings
has an area of 25 m². If the speed of air is 180 km/h over the lower
(b)​

Answer 1

Answer:

Answer

The area of the wings of the plane, A=2×25=50sq−m

Speed of air over the lower wing, V

1

=180km/h=50m/s

Speed of air over the upper wing, V

2

=234km/h=65m/s

Density of air, =1kg/cu.m

Pressure of air over the lower wing =P

1

Pressure of air over the upper wing =P

2

The upward force on the plane can be obtained using Bernoullis equation as:

P

1

−P

2

=

2

1

ρ(V

2

2

−V

1

2

)

F=(P

1

−P

2

)A=

2

1

ρ(V

2

2

−V

1

2

)A

F=(P

1

−P

2

)A=

2

1

×1×(65

2

−50

2

)×50=43125N

∴m=

g

F

=4400kg