Ask question

Ask question

All categories

3 years ago

5

When the air under the envelope is heated, the balloon lifts. Which of the following statements is true? A) hot air balloons use

radiation to rise B) hot air balloons use conduction to rise C) hot air balloons use convection to rise D) hot air balloons use air resistance to rise

2 answers:

Bond [772]3 years ago

4 0

The hot air balloon uses convection to rise

butalik [34]3 years ago

3 0

C) hot air balloons use convection to rise

when air under the envelope is heated, it travels upward and it is less dense as compared to the air in the surrounding . This difference in density values of air inside and outside creates force of buoyancy which make the balloon to get lifted. since here the air is being heated and it is transporting the thermal energy with it, this process is called convection. hence we say that hot air balloons use convection to rise.

You might be interested in

Suppose someone pours 0.250 kg of 20.0ºC water (about a cup) into a 0.500-kg aluminum pan with a temperature of 150ºC. Assume th

Troyanec [42]

Answer : The temperature when the water and pan reach thermal equilibrium short time later is, $59.10^oC$

Explanation :

In this problem we assumed that heat given by the hot body is equal to the heat taken by the cold body.

$q_1=-q_2$

$m_1\times c_1\times (T_f-T_1)=-m_2\times c_2\times (T_f-T_2)$

where,

$c_1$ = specific heat of aluminium = $0.90J/g^oC$

$c_2$ = specific heat of water = $4.184J/g^oC$

$m_1$ = mass of aluminum = 0.500 kg = 500 g

$m_2$ = mass of water = 0.250 kg = 250 g

$T_f$ = final temperature of mixture = ?

$T_1$ = initial temperature of aluminum = $150^oC$

$T_2$ = initial temperature of water = $20^oC$

Now put all the given values in the above formula, we get:

$500g\times 0.90J/g^oC\times (T_f-150)^oC=-250g\times 4.184J/g^oC\times (T_f-20)^oC$

$T_f=59.10^oC$

Therefore, the temperature when the water and pan reach thermal equilibrium short time later is, $59.10^oC$

8 0

3 years ago

Kenitic Energy (KE)<br> 1.doubled

astra-53 [7]

Answer:

mass

Explanation:

This energy of motion is what we call kinetic energy. ... In fact, kinetic energy is directly proportional to mass: if you double the mass, then you double the kinetic energy. Second, the faster something is moving, the greater the force it is capable of exerting and the greater energy it possesses.

pls make as brainlieast

3 0

2 years ago

How are size and mass of the moon different from that of the earth?

Elodia [21]

<span>The diameter of the Moon is 3,474 km. Now, let's compare this to the Earth. The diameter of the Earth is 12,742 km. This means that the Moon is approximately 27% the size of the Earth.</span>

3 0

2 years ago

A spinning turbine can generate electricity only in the form of a/an _______ current.

lukranit [14]

Answer:

A spinning turbine can generate electricity only in the form of an alternating current.

8 0

2 years ago

A 1.5 kg cart is attached to a spring with spring constant of 5 N/m. The cart & spring is pulled to stretch the spring by 3

vaieri [72.5K]

22.5 J

Explanation:

Given:

x = 3 m

$k = 5\:\text{N/m}$

The spring potential energy $PE_s$ is

$PE_s = \frac{1}{2}kx^2 = \frac{1}{2}(5\:\text{N/m})(3\:\text{m})^2$

$\:\:\:\:\:\:\:=22.5\:\text{J}$

3 0

2 years ago