Explanation:
It is given that,
Average power per unit mass generated by Lance, ![\dfrac{P}{m}=6.5\ W/kg](https://tex.z-dn.net/?f=%5Cdfrac%7BP%7D%7Bm%7D%3D6.5%5C%20W%2Fkg)
![P=6.5\times 75=487.5\ W](https://tex.z-dn.net/?f=P%3D6.5%5Ctimes%2075%3D487.5%5C%20W)
(a) Distance to cover race, ![d = 160\ km =160\times 10^3\ m](https://tex.z-dn.net/?f=d%20%3D%20160%5C%20km%20%3D160%5Ctimes%2010%5E3%5C%20m)
Average speed of the person, v = 11 m/s
If t is the time taken to cover the race.
![t=\dfrac{d}{v}](https://tex.z-dn.net/?f=t%3D%5Cdfrac%7Bd%7D%7Bv%7D)
![t=\dfrac{160\times 10^3\ m}{11\ m/s}](https://tex.z-dn.net/?f=t%3D%5Cdfrac%7B160%5Ctimes%2010%5E3%5C%20m%7D%7B11%5C%20m%2Fs%7D)
t = 14545.46 s
Let W is the work done. The relation between the work done and the power is given by :
![P=\dfrac{W}{t}](https://tex.z-dn.net/?f=P%3D%5Cdfrac%7BW%7D%7Bt%7D)
![W=P\times t](https://tex.z-dn.net/?f=W%3DP%5Ctimes%20t)
![W=487.5\times 14545.46](https://tex.z-dn.net/?f=W%3D487.5%5Ctimes%2014545.46%20)
W = 7090911.75 J
(b) Since, ![1\ J=2.389\times 10^{-4}\ calories](https://tex.z-dn.net/?f=1%5C%20J%3D2.389%5Ctimes%2010%5E%7B-4%7D%5C%20calories)
So, in 7090911.75 J, ![W=7090911.75 \times 2.389\times 10^{-4}](https://tex.z-dn.net/?f=W%3D7090911.75%20%5Ctimes%202.389%5Ctimes%2010%5E%7B-4%7D)
W = 1694.01 J
Hence, this is the required solution.
A research question that would complete the third question you need that are related to the first 2 questions which are:
- “what type of masks help prevent fog on glasses when breathing?”
- “does a mask’s material affect the level of fog on glasses as an effect of breathing?”
Would be: "Are there any available masks that could prevent fog on glasses that could be improved upon"?
This new research question would help you find out if there is an already existing mask that could be made better.
<h3>What is a Research Question?</h3>
This refers to "a question that a research project sets out to answer". and seeks to give answers to particular phenomena.
Hence, we can see that the new research question Would be: "Are there any available masks that could prevent fog on glasses that could be improved upon"?
This new research question would help you find out if there is an already existing mask that could be made better.
Read more about research questions here:
brainly.com/question/25257437
#SPJ1
Answer:
Explanation:
Given
Density of Cork ![\rho _c=0.25\rho _{water}](https://tex.z-dn.net/?f=%5Crho%20_c%3D0.25%5Crho%20_%7Bwater%7D)
Considering V be the volume of Cork
Buoyant Force will be acting Upward and Weight is acting Downward along with T
Since density of water is more than cork therefore Cork will try to escape out of water but due to tension it will not
we can write as
![\rho _{water}Vg-\rho _Cvg-T=0](https://tex.z-dn.net/?f=%5Crho%20_%7Bwater%7DVg-%5Crho%20_Cvg-T%3D0)
where T=tension
Thus Tension T is
![T=Vg(\rho _{water}-\rho _c)](https://tex.z-dn.net/?f=T%3DVg%28%5Crho%20_%7Bwater%7D-%5Crho%20_c%29)
Taking
common
![T=mg(\frac{\rho _{water}}{\rho _c}-1)](https://tex.z-dn.net/?f=T%3Dmg%28%5Cfrac%7B%5Crho%20_%7Bwater%7D%7D%7B%5Crho%20_c%7D-1%29)
![T=mg(4-1)](https://tex.z-dn.net/?f=T%3Dmg%284-1%29)
![T=3mg](https://tex.z-dn.net/?f=T%3D3mg)