Answer:
The time of oil tanker will be 80 sec.
Step-by-step explanation:
Given that,
He walks at 3 km/hour.
If the container ship is 100 m long, and travelling at 12 km/hour.
The distance will be 200 m.
We need to calculate the relative velocity
Using formula of relative velocity
![v_(21)=v_(2)-v_(1)](https://img.qammunity.org/2021/formulas/advanced-placement-ap/high-school/v2mvmlu9audayjv7dq3fhtj152xru3nnpf.png)
Put the value into the formula
![v_(21)=12-3](https://img.qammunity.org/2021/formulas/advanced-placement-ap/high-school/prz7ijmje4ratmduxwaw1sxhjw01x3a394.png)
![v_(21)=9\ km/h](https://img.qammunity.org/2021/formulas/advanced-placement-ap/high-school/v8m6lqnrvzpq396cw2v4zuco0npk5qut53.png)
The distance is 200 m.
We need to calculate the time
Using formula of time
![v=(d)/(t)](https://img.qammunity.org/2021/formulas/physics/college/yb8yhxfd0dloytbyvzh6g8royin8sowug7.png)
![t=(d)/(v)](https://img.qammunity.org/2021/formulas/physics/college/cwq2qxh5njqmlzqcaa110w0i173l35zgms.png)
Put the value into the formula
![t=(200)/(9*(5)/(18))](https://img.qammunity.org/2021/formulas/advanced-placement-ap/high-school/azj04bxcjzkn8vcx9tau6gxtr02yo5btwm.png)
![t=80 sec](https://img.qammunity.org/2021/formulas/advanced-placement-ap/high-school/njchw86n8q9nlxxmbrndllmbmab3lwfdr1.png)
Hence, The time of oil tanker will be 80 sec.