3. How do you think a hot air balloon works?
1 answer:
You might be interested in
Answer:
<em>The hotter star radiates 625 times more energy per second from each square meter of its surface</em>
<em></em>
<em></em>
Explanation:
Temperature of the hotter star is 30000 K
temperature of the cooler star = 6000 K
From Stefan-Boltzmann radiation laws, for a non black body
P = εσA
where
P is the energy per second or power of radiation
ε is the emissivity of the body
σ is the Stefan-Boltzmann constant of proportionality
A is the area of the sun
T is the temperature of the sun
The sun can be approximated as a black body, and the equation reduces to
P = σA
For the hotter body,
P = σA() = 8.1 x 10^17σA J/s
For the cooler body,
P = σA() = 1.296 x 10^15σA J/s
comparing the two stars energy
==> (8.1 x 10^17)/(1.296 x 10^15) = 625
<em>This means that the hotter star radiates 625 times more energy per second from each square meter of its surface</em>
<em></em>
Answer:
a
The focal length of the lens in water is
b
The focal length of the mirror in water is
Explanation:
From the question we are told that
The index of refraction of the lens material =
The index of refraction of the medium surrounding the lens =
The lens maker's formula is mathematically represented as
Where is the focal length
is the index of refraction
are the radius of curvature of sphere 1 and 2 of the lens
From the question When the lens in air we have
When immersed in liquid the formula becomes
The ratio of the focal length of the the two medium is mathematically evaluated as
From the question
= 79.0 cm
and the refractive index of water(material surrounding the lens) has a constant value of
b
The focal length of a mirror is dependent on the concept of reflection which is not affected by medium around it.
Answer:
The intensity of the net electric field will:
Explanation:
Here we need first find the electric field due to the first charge at the midway point.
The electric field equation is given by:
Where:
- k is Coulomb's constant
- q(1) is 20.00 μC or 20*10⁻⁶ C
- d is the distance from q1 to the midpoint (d=10.0 cm)
So, we will have:
The direction of E1 is to the right of the midpoint.
Now, the second electric field is:
The direction of E2 is to the right of the midpoint because the second charge is negative.
Finally, the intensity of the net electric field will:
I hope it helps you!