Part 1

Question 1

What is the hydrostatic equation?

Answer 1

𝑑𝑝/dℎ = −𝜌𝑔

Question 2

What is geopotential altitude?

Answer 2

A measure of specific potential energy at a given height, adjusted for varying gravity.

Question 3

What is the relationship between geometric and geopotential altitude?

Answer 3

ℎ = r ⋅ ℎ𝐺/r + ℎ𝐺

Question 4

What is the temperature variation in the troposphere?

Answer 4

Linear decrease with altitude (gradient region).

Question 5

What is the temperature variation in the stratosphere?

Answer 5

Constant temperature (isothermal region).

Question 6

In the gradient layer, how do you calculate pressure variation?

Answer 6

𝑝/p1 = (𝑇/T1)^(−𝑔/𝑎𝑅)

Question 7

In the isothermal layer, how is pressure calculated?

Answer 7

𝑝/p1 = exp(−𝑔(ℎ−ℎ1)/𝑅𝑇)

Question 8

What are pressure, temperature, and density altitudes?

Answer 8

Altitudes at which standard atmospheric tables match the measured p, T, and ρ.

Question 9

What is absolute pressure?

Answer 9

Pressure relative to vacuum:

p_abs = p_gauge + p_atm

Question 10

What is gauge pressure?

Answer 10

Pressure relative to atmospheric pressure.

Question 11

What is dynamic pressure?

Answer 11

q = 1/2 ρv²

Question 12

What is total pressure?

Answer 12

p_t = p_s + q (static + dynamic)

Question 13

How does a U-tube manometer work?

Answer 13

Measures pressure difference via fluid height:

Δp = ρgh

Question 14

How does an inclined manometer increase sensitivity?

Answer 14

By using angle α:

Δp = ρgLsin(α)

Question 15

What pressure does a barometer measure?

Answer 15

Atmospheric pressure:

p = ρgh (with mercury column)

Question 16

What is the buoyant force on a body?

Answer 16

𝐹𝐵 = (𝜌air − 𝜌body)gV

Question 17

What makes a body rise due to buoyancy?

Answer 17

Its density is less than the surrounding fluid.

Question 18

Buoyancy force formula for helium balloon:

Answer 18

𝐹𝐵 = (𝜌air − 𝜌He)gH⋅A − W

Question 19

Buoyancy force for hot air balloon:

Answer 19

𝐹𝐵 = (𝜌cold air − 𝜌hot air)gH⋅A − W

Question 20

What is neutral buoyancy?

Answer 20

𝜌balloon = 𝜌air, so 𝐹𝐵 = 0

Question 21

How does temperature affect buoyancy in hot air balloons?

Answer 21

Higher T → Lower ρ → Higher buoyancy