Item 1 A vertical solid steel post of diameter d = 28 cm and length L = 2.10 m i

Question

Item 1

A vertical solid steel post of diameter d = 28 cm and length L = 2.10 m is required to support a load of mass m = 7800 kg . You can ignore the weight of the post. Take free fall acceleration to be g=9.8m/s2.

Part B

What is the strain in the post?

Express your answer using two significant figures.

SubmitMy AnswersGive Up

Incorrect; One attempt remaining; Try Again

Part C

What is the change in the post's length when the load is applied?

Express your answer using two significant figures.

Item 1

A vertical solid steel post of diameter d = 28 cm and length L = 2.10 m is required to support a load of mass m = 7800 kg . You can ignore the weight of the post. Take free fall acceleration to be g=9.8m/s2.

Part B

What is the strain in the post?

Express your answer using two significant figures.

L/L =

SubmitMy AnswersGive Up

Incorrect; One attempt remaining; Try Again

Part C

What is the change in the post's length when the load is applied?

Express your answer using two significant figures.

L =   m  

Explanation / Answer

We know that:

Young's modulus = Stress/Strain

Stress = F/A

Strain = dL/L

Y = F*L/(A*dL)

A.

Stress = dL/L = F/(A*Y)

Now using given values:

F = mg = 7800*9.81

A = pi*r^2 = pi*0.14^2

Y = 200*10^9

So,

dL/L = 7800*9.81/(pi*0.14^2*200*10^9) = 6.21*10^-6

B.

dL = L*strain

dL = 2.1*6.21*10^-6 = 1.3*10^-5 m

Related Questions

Navigate

• Browse (All)
• Browse I
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.