To solve this problem we need the concepts of Energy fluency and Intensity from chemical elements.
The energy fluency is given by the equation

Where
The energy fluency
c = Activity of the source
r = distance
E = electric field
In the other hand we have the equation for current in materials, which is given by

Then replacing our values we have that


We can conclude in this part that 1.3*10^7Bq is the activity coming out of the cylinder.
Now the energy fluency would be,



The uncollided flux density at the outer surface of the tank nearest the source is 
Answer: touch the pan to the burner
Explanation:
There are three modes of heat transfer:
conduction, convection and radiation.
For conduction, the heat transfers from a hot object to a cold object when the two are in contact.
For convection there is bulk motion of fluid occurs which transfers the heat.
For heat transfer by radiation, medium is not required.
Thus, to demonstrate conduction between pan and burner, the pan must touch the burner.
Explanation:
Given:
u = 20 m/s
a = 5 m/s^2
v = 30 m/s
t = ?
Use the first kinematic equation of motion:
v = u + at
t = (v - u)/a = 10/5 = 2 seconds
Answer:
The answer is 4200 J.
Explanation:
The formula of work done is, W = F×D where F is the force of an object and D is the distance. Then you just substitute the values into the equation :
W = F×D
F = 42N
D = 100m
W = 42 × 100
= 4200 J
if there were no invention of machines then life would have been more difficult and simple works could be hard to do. Even now we are using our phones, sitting in a AC room interacting to eachother from different places. without the invention of machines simple things like transportation would have been difficult. There would be horses and donkey for the transportation. There would be no electricity,no internet, no transportation, not even c computers or mobile etc. The market for business will be smaller, the knowledge and news about world would be less.
so the problem would have been bigger than we can imagine. But one thing is that nature could survive lot more compared to what we have done till now by destroying nature.