A man pushes a couch across the room is the answer!
1) A The 78g
2) C Push on the wagon in the opposite direction as Jack with a force that is the same as Jack is applying.
An isolated system , it does not allow any matter or energy to be exchanged
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


