Some elements that have a symbol entirely different from the spelling are..
1.Fe. Iron
2.Na.Sodium
3.K. Pottasium
4.Ag.Silver
5.Sn.Tin
6.Sb. Antimony
7,Pb.Lead
Complete Question
The complete question is shown on the uploaded image
Answer:
The tension on the shank is 
Explanation:
From the question we are told that
The strain on the strain on the head is 
The contact area is
Looking at the first diagram
At 600 MPa of stress
The strain is 
At 450 MPa of stress
The strain is 
To find the stress at
we use the interpolation method

Substituting values



Generally the force on each head is mathematically represented as

Substituting values


Now the tension on the bolt shank is as a result of the force on the 6 head which is mathematically evaluated as



Traveling against currents usually takes longer. Kinda like walking against the wind, you feel the heaviness against your jacket as you push through it. Where when you walking with the wind, it kind of gives your a push. Same for with currents.
Those forces are exactly equal.
Gravity always works as a pair of <em>EQUAL</em> forces ... one in each direction
between two masses. Your weight on the Earth is exactly the same as
the Earth's weight on you.