"The equation can be used to calculate the power absorbed by any surface" statement concerning the Stefan-Boltzmann equation is correct.
Answer: Option A
<u>Explanation:</u>
According to Stefan Boltzmann equation, the power radiated by black body radiation source is directly proportionate to the fourth power of temperature of the source. So the radiation transferred is absorbed by another surface and that absorbed power will also be equal to the fourth power of the temperature. So the equation describes the relation of net radiation loss with the change in temperature from hotter temperature to cooler temperature surface.
So this law is application for calculating power absorbed by any surface.
Answer:
b) se duplica
Explanation:
The disk is moving with constant angular velocity, let's call it 
.
The linear velocity of a point on the disk is given by
where r is the distance of the point from the axis of rotation.
In this problem, the object is moved at a distance twice as far as the initial point, so
Therefore, the new linear velocity is
So, the velocity has doubled, and the correct answer is
b) se duplica
Answer:
The correct answer is D. s₂=4s₁
Explanation:
The distance of a particle is given by:
where
s₀ is the initial position when t=0
v₀ is the initial speed when t=0
a is the constant acceleration
t is the time in seconds
Then, the position s₁ is given by:
As the particle starts from rest v₀=0 and we consider s₀=0, s₁ will be:
Furthermore, the position s₂ is:
In this case t₁=10 s and t₂=20 s (10 seconds later). In other words t₂=2t₁.
We replace the value of t₂ in the second equation (s₂):
Finally, we divide s₂ by s₁ to get the ratio:
