6 public questions tagged with this topic.
Dynamic lift (e.g., on airplane wings) results from a pressure difference due to faster airflow above (Bernoulli’s principle), not viscosity or gravitational force alone. The incorrect statement is that it’s due to viscosity.
Ref: NCERT Class 11 Physics, Thermal Properties and Gravitation.
ΔP⋅A = mg. mg = 4.5×105×9.8 = 4.41×106N, A = 600m2. ΔP = 4.41×106600 = 7350Pa. As per NCERT, applying relevant law/formula with correct units and sign convention leads to 7350 Pa. This satisfies dimensional consistency and physical conditions given, so option C is scientifically correct.
Ref: NCBI Bookshelf, Ideal Gas Law: P1V1/T1 = P2V2/T2.
ΔP⋅A = mg. mg = 4.0×105×9.8 = 3.92×106N, A = 600m2. ΔP = 3.92×106600 = 6533.33Pa≈6533Pa. As per NCERT, applying relevant law/formula with correct units and sign convention leads to 6533 Pa. This satisfies dimensional consistency and physical conditions given, so option C is scientifically correct.
Ref: NCBI Bookshelf, Ideal Gas Law: P1V1/T1 = P2V2/T2.
ΔP⋅A = mg, mg = 2.5×105×10 = 2.5×106N. A = 400m2. ΔP = 2.5×106400 = 6250Pa. As per NCERT, applying relevant law/formula with correct units and sign convention leads to 6250 Pa. This satisfies dimensional consistency and physical conditions given, so option B is scientifically correct.
Ref: NCBI Bookshelf, Ideal Gas Law: P1V1/T1 = P2V2/T2.
The aerofoil shape causes air to move faster over the top than underneath, reducing pressure above (Bernoulli’s principle) and creating a pressure difference that lifts the plane, known as dynamic lift.
Ref: NCERT Class 11 Physics, Thermal Properties and Gravitation.
ΔP⋅A = mg. mg = 2.5×105×9.8 = 2.45×106N, A = 500m2. ΔP = 2.45×106500 = 4900Pa. As per NCERT, applying relevant law/formula with correct units and sign convention leads to 4900 Pa. This satisfies dimensional consistency and physical conditions given, so option C is scientifically correct.
Ref: NCBI Bookshelf, Ideal Gas Law: P1V1/T1 = P2V2/T2.
