Answer:
a
Explanation:
The most reasonable conclusion of the above phenomenon is that water is a poor conductor of heat. Basically water is an insulator. The heat from surface to the bottom of the beaker will take a lot of time. Moreover, no convection current is formed so, heat might not even reach the bottom surface. Hydrogen bonding also play a vital role in determining the thermal properties of water.
hence option A is correct
A climograph is a graphical representation of a location's basic climate. Clinograph is an instrument used to draw parallel lines to the inclined lines. It contains one adjustable wing or strip which can be adjusted to required angle. So, it can be termed as adjustable set square
Hope this helps!:)
Answer: Planting a tree belt.
Explanation:
The most effective method by which the desertification of the soil can be controlled is by planting more and more trees.
The process of desertification occurs when there is a loss of vegetation, water bodies and animals from a particular area. Loss of trees makes the area look like desert.
So, planting trees along with some irrigation will help to cope with problem.
Answer:
i think it is car B because the greater the speed, the greater the drag force acting on the vehicle
Explanation:
Answer:
(a) ![[Y_{p} ]_{max} = \frac{2f}{1+f}](https://tex.z-dn.net/?f=%5BY_%7Bp%7D%20%5D_%7Bmax%7D%20%3D%20%5Cfrac%7B2f%7D%7B1%2Bf%7D)
(b) 
; ![[Y_{p} ]_{max}](https://tex.z-dn.net/?f=%5BY_%7Bp%7D%20%5D_%7Bmax%7D%20)
= 0.026
Explanation:
Since the neutron-to-proton ratio at the time of nucleosynthesis is given:
Therefore:
Then, to determine the maximum ⁴He fraction if all the available 
neutrons bind to all the protons. Since, there are 2 protons and 2 neutrons in a ⁴He nucleus, it shows that there would be 
nuclei of ⁴He.
In addition, a ⁴He nucleus has a mass of 
, where 
is the mass of one proton. Thus, nuclei of such nuclei will have a mass of *.
Assuming that 
, there would be a total of 
protons and neutrons with a total mass of 
.
Thus:
(b) Given:
; τ
= 3*60s = 180 s
![f_{new} = \frac{n_{nf} }{n_{pf} } = \frac{exp (-200/180)}{5 +[1- exp(-200/180)]} =\frac{0.077}{5.923} = 0.013](https://tex.z-dn.net/?f=f_%7Bnew%7D%20%3D%20%5Cfrac%7Bn_%7Bnf%7D%20%7D%7Bn_%7Bpf%7D%20%7D%20%3D%20%5Cfrac%7Bexp%20%28-200%2F180%29%7D%7B5%20%2B%5B1-%20exp%28-200%2F180%29%5D%7D%20%3D%5Cfrac%7B0.077%7D%7B5.923%7D%20%3D%200.013)
= (2*0.013)/(1+0.013) = 0.026
