Ask question

Ask question

All categories

3 years ago

11

A hot-air balloon consists of a basket hanging beneath a large envelope filled with hot air. A typical hot-air balloon has a tot

al mass of 539 kg, including passengers in its basket, and holds 2.62 ✕ 103 m3 of hot air in its envelope. If the ambient air density is 1.27 kg/m3, determine the density (in kg/m3) of hot air inside the envelope when the balloon is neutrally buoyant. Neglect the volume of air displaced by the basket and passengers. HINT kg/m3

1 answer:

Deffense [45]3 years ago

4 0

Answer:

1.05045 kg/m³

Explanation:

$\rho_a$ = Density of air = 1.26 kg/m³

$\rho_{ha}$ = Density of hot air

$m_a$ = Mass of balloon = 539 kg

g = Acceleration due to gravity = 9.81 m/s²

v = Volume of air in balloon = $2.62\times 10^3\ m^3$

The net force on the balloon will be

$F_n=(\rho_a-\rho_{ha})vg$

Also

$F_n=m_ag$

$\\\Rightarrow 549g=(\rho_a-\rho_{ha})vg\\\Rightarrow 549=(1.26-\rho_{ha})2.62\times 10^3\\\Rightarrow -\rho_{ha}=\frac{549}{2.62\times 10^3}-1.26\\\Rightarrow \rho_{ha}=1.05045\ kg/m^3$

The density of hot air inside the envelope is 1.05045 kg/m³

You might be interested in

3. Write any two types of force.

Lerok [7]

Answer:

An <u>applied force</u> is a force that is applied to an object by a person or another object. If a person is pushing a desk across the room, then there is an applied force acting upon the object. The applied force is the force exerted on the desk by the person.

A <u>friction force</u> is the force exerted by a surface as an object moves across it or makes an effort to move across it. There are at least two types of friction force - sliding and static friction. Though it is not always the case, the friction force often opposes the motion of an object. For example, if a book slides across the surface of a desk, then the desk exerts a friction force in the opposite direction of its motion. Friction results from the two surfaces being pressed together closely, causing intermolecular attractive forces between molecules of different surfaces. As such, friction depends upon the nature of the two surfaces and upon the degree to which they are pressed together. The maximum amount of friction force that a surface can exert upon an object can be calculated using the formula below:

$F_{frict}$ = µ • $F_{norm}$

8 0

2 years ago

What makes a planet different from other celestial bodies? SIMPLE WORDS>

Gwar [14]

Answer:

don't know her boi I'm finna glow october

4 0

3 years ago

How to find the magnitude and direction of a resultant velocity?

mixas84 [53]

Find the horizontal components vcos30 ...one goes right and one goes left so they cancel each other.
Find vertical components vsin30.....there are two of them.... so 2vcos30....hey presto... resultant velocity = 2vCos30

5 0

3 years ago

An insulated rigid tank contains 3 kg of H2O in the form of a saturated mixture of liquid and vapor at a pressure of 150 kPa and

Andre45 [30]

Answer:

change in entropy is 1.44 kJ/ K

Explanation:

from steam tables

At 150 kPa

specific volume

Vf = 0.001053 m^3/kg

vg = 1.1594 m^3/kg

specific entropy values are

Sf = 1.4337 kJ/kg K

Sfg = 5.789 kJ/kg

initial specific volume is calculated as

$v_1 = vf + x(vg - vf)$

$= 0.001053 + 0.25(1.1594 - 0.001053)$

$v_1 = 0.20964 m^3/kg$

$s_1 = Sf + x(Sfg)$

$= 1.4337 + 0.25 \times 5.7894 = 2.88 kJ/kg K$

FROM STEAM Table

at 200 kPa

specific volume

Vf = 0.001061 m^3/kg

vg = 0.88578 m^3/kg

specific entropy values are

Sf = 1.5302 kJ/kg K

Sfg = 5.5698 kJ/kg

constant volume so $v_1 - v_2 = 0.29064 m^3/kg$

$v_2 = v_1 = vf + x(vg - vf)$

$=0.29064 = x_2(0.88578 - 0.001061)$

$x_2 = 0.327$

$s_2 = 1.5302 + 0.32 \times 5.5968 = 3.36035 kJ/kg K$

Change in entropy $\Delta s = m(s_2 - s_1)$

=3( 3.36035 - 2.88) = 1.44 kJ/kg

8 0

3 years ago

Imagine you have to design a safe, useful device that uses an electric discharge to make your life better. How would you describ

Norma-Jean [14]

Answer:

i would describe it as some thing that keeps ur belongings safe and can also make my life better and not so sad

Explanation:

4 0

3 years ago

Read 2 more answers