If 1 ken is 1.97 meter, then 1 square ken is 3.8809 square meters, and one cubic ken is 7.645373. As for the cylindrical tank, the volume of it would be 10.835 times the radius of the cylinder time 1.97^2 times pi. As you didn't specify the radius, I can't give the exact answer but that would be how to get it.
Answer:B 20 newtons opposite to the direction of the applied force
Explanation:
The object's speed will remain constant after the it leaves his hand.
So will HIS speed in the opposite direction.