60 days, tell me if I'm correct please.
"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:

Explanation:
Given

r=2cm
Now angular velocity is given by 

Now linear velocity(v) is given =

Now tangential component of acceleration is given by

at t=0

radial component of acceleration is given by



at t=0

The power required is 1.6 kW.
Answer:
Explanation:
Power is defined as the amount of work done on any object for a given time interval. In other words, power is the amount of force required to move an object in a given period of time.
Power = Work done / time taken for that work done.
Here the force is given as 800 N and the displacement is given as 2.5 m, while the time required for the displacement is given as 1.22 seconds.
So the power will be ratio of the product of force acting on the weightlifter, displacement of the weight to the time taken for that displacement.
Power = (800×2.5)/1.22 =1639 W
So the power required is 1.6 kW.
Answer:
D
Explanation:
You should compare your results and data with your original hypothesis. It is okay to have a hypothesis that was shown to be false. That's science. Things do not always work out. You can always discuss what you could have done differently and things that went wrong. There is no right answer in science!