Explanation

Bernoulli’s principle is based on conservation of energy in flowing fluids.

P+1/2 ρv2+ρgh=constant

For airplane wings:

• P = Pressure
• ρ (rho) = Density of air
• v = Speed of air
• g = Gravitational acceleration
• h = Height
• Higher air speed → Lower pressure
• Lower air speed → Higher pressure
• Pressure difference between the upper and lower surfaces creates lift.
• Lift acts upward and helps the airplane fly

Explanation

• Earth’s gravity provides the force that keeps satellites in orbit.
• This gravitational force pulls the satellite toward Earth.
• The satellite’s forward motion makes it continuously fall around Earth rather than directly into it.
• Newton’s Law of Gravitation explains this gravitational attraction.

Explanation

• The nucleus contains the cell’s genetic material (DNA).
• DNA carries hereditary information.
• The nucleus controls many cell activities.
• In prokaryotic cells (like bacteria), DNA is not enclosed in a nucleus; it is found in the nucleoid region.
• Genetic material = DNA.

Explanation

• The SI unit of energy is the Joule (J).
• It is the unit of energy, work, and heat.

Additional information:

• 1 Joule (J) = 1 Newton × 1 meter
• Calorie – 1 cal = 4.184 J
• Kilowatt-hour (kWh) – 1 kWh = 3.6 × 10⁶ J
• Electronvolt (eV) – 1 eV ≈ 1.602 × 10⁻¹⁹ J
• Erg (CGS unit) – 1 erg = 10⁻⁷ J

Last verified on 17-01-2026