Answer:
a - As long as the time between 2 events is reconcilable with a light signal, the time between the events, in that frame, can be determined.
To solve this problem it is necessary to apply the concepts related to the Stefan-Boltzmann law which establishes that a black body emits thermal radiation with a total hemispheric emissive power (W / m²) proportional to the fourth power of its temperature.
Heat flow is obtained as follows:

Where,
F =View Factor
A = Cross sectional Area
Stefan-Boltzmann constant
T= Temperature
Our values are given as
D = 0.6m

The view factor between two coaxial parallel disks would be


Then the view factor between base to top surface of the cylinder becomes
. From the summation rule


Then the net rate of radiation heat transfer from the disks to the environment is calculated as





Therefore the rate heat radiation is 780.76W
Extensional stress. is your answer.
Answer:
c
Explanation:
cuz its informing the length of 5 and weight on 20N
We do not feel the gravitational forces from objects other than the Earth because they are weak.