Prepare for NEET Physics Mechanical Properties Of Fluids (Dynamic Lift) with MCQs & PYQs on NEET.GUIDE. Access free practice, previous year questions, and expert solutions to understand lift forces on wings and airfoils.
NEET Questions / Physics / Mechanical Properties Of Fluids / Dynamic Lift
A small airplane with a wingspan of 10 m is flying at a speed of 72 km/h. The difference in air pressure below and above the wings is measured to be 500 Pa. Assuming the lift force is entirely due to the pressure difference and acts perpendicular to the wings, what is the mass of the airplane? (Take air density as 1.2 kg/mยณ)
1020 kg
1200 kg
Cannot be determined without the wing area. If the wing area is 'A' mยฒ, then the mass is 51.02*A kg.
1500 kg
An aircraft is flying at a constant altitude and velocity. Which of the following statements is INCORRECT regarding the lift generated by its wings?
The lift generated is equal to the weight of the aircraft.
The lift coefficient remains constant.
The angle of attack remains constant.
The lift generated is directly proportional to the square of the angle of attack.
A helicopter with a rotor blade length of 5m is hovering in still air. The downward velocity of air pushed by the rotor is 10 m/s. If the density of air is 1.2 kg/mยณ, what is the approximate mass of the helicopter? (Assume the entire rotor disc area contributes to lift)
471 kg
942 kg
1884 kg
3768 kg
Consider two identical airplanes, one flying at a low altitude where the air density is high, and the other at a high altitude where the air density is low. Both are flying at the same speed. Which requires a greater angle of attack to maintain level flight?
The airplane at low altitude
The airplane at high altitude
Both require the same angle of attack
Angle of attack is not relevant in this scenario
How does the velocity of air over the top surface of a wing generating lift compare to the velocity of air under the bottom surface?
The velocity over the top surface is significantly higher.
The velocity under the bottom surface is significantly higher.
The velocities are approximately equal.
The velocity difference is negligible for lift generation.
A bird with a mass of 0.5 kg is soaring at a constant speed. Its wings have a combined surface area of 0.1 mยฒ. Assuming the air density is 1.2 kg/mยณ and the pressure difference between the top and bottom surfaces of the wings is 40 Pa, what is the average downward velocity of air deflected by the bird's wings? (Assume all lift is due to downward air deflection).
2.89 m/s
5.77 m/s
8.17 m/s
11.09 m/s
Which principle is fundamentally responsible for the dynamic lift experienced by an airplane wing?
Bernoulli's principle
Archimedes' principle
Pascal's law
Newton's third law
The shape of an airplane wing is designed such that the airspeed is ____ over the top surface compared to the bottom surface.
higher
lower
equal
unpredictable
Dynamic lift is primarily dependent on the ______ of the airflow.
speed
density
temperature
humidity
The angle of attack of an airplane wing refers to the angle between the wing and the:
relative wind
ground
horizon
airplane's fuselage
