Thermal Deformations
Mechanics of Materials · FE Reference Handbook section
Core formulas for this FE topic
Definitions, applicability, units, assumptions and worked examples for each relation.
Worked exam-style examples
The four ways this section is written on the real exam — thoughts first, then equations, then substitution.
A mechanics of materials problem uses Axial elongation. Given axial load (P) = 85.0000 kip; length (L) = 108.0 in; area (A) = 4.1000 in²; modulus (E) = 29,000 ksi, determine the elongation (delta) in in.
Given
Find
elongation (delta), in in
Start with the thinking
- The governing relation printed in this handbook section is Axial elongation.
- Everything except delta is given, so isolate delta symbolically first — never rearrange after the numbers are in.
- Tabulate each given with its unit and confirm the units are consistent with the relation before substituting.
- Mechanics of Materials items reward recognising the unknown before touching a calculator.
Step-by-step solution
Step 1 — State the governing relation:
Step 2 — Rearrange the relation so that delta stands alone on the left-hand side.
Step 3 — List the givens: axial load (P) = 85.0000 kip, length (L) = 108.0 in, area (A) = 4.1000 in², modulus (E) = 29,000 ksi.
Step 4 — Substitute the given values into the rearranged relation.
Step 5 — Evaluate:
Step 6 — Check: returning delta = 0.0772 in to
reproduces the given quantities, and both sides carry the same units.
Why the other options are there
- 0.1544 — kept a factor of two that cancels in the correct rearrangement.
- 0.0386 — dropped that same factor in the other direction.
- 0.0849 — rounded an intermediate value before the final step.
Reference: FE Reference Handbook — Mechanics of Materials → Thermal Deformations
A mechanics of materials problem uses Axial elongation. Given length (L) = 129.0 in; area (A) = 5.9000 in²; modulus (E) = 17,000 ksi; elongation (delta) = 0.9995 in, determine the axial load (P) in kip.
Given
Find
axial load (P), in kip
Start with the thinking
- The governing relation printed in this handbook section is Axial elongation.
- Everything except P is given, so isolate P symbolically first — never rearrange after the numbers are in.
- Tabulate each given with its unit and confirm the units are consistent with the relation before substituting.
- Mechanics of Materials items reward recognising the unknown before touching a calculator.
Step-by-step solution
Step 1 — State the governing relation:
Step 2 — Rearrange the relation so that P stands alone on the left-hand side.
Step 3 — List the givens: length (L) = 129.0 in, area (A) = 5.9000 in², modulus (E) = 17,000 ksi, elongation (delta) = 0.9995 in.
Step 4 — Substitute the given values into the rearranged relation.
Step 5 — Evaluate:
Step 6 — Check: returning P = 777.1 kip to
reproduces the given quantities, and both sides carry the same units.
Why the other options are there
- 1,554 — kept a factor of two that cancels in the correct rearrangement.
- 388.6 — dropped that same factor in the other direction.
- 854.8 — rounded an intermediate value before the final step.
Reference: FE Reference Handbook — Mechanics of Materials → Thermal Deformations
A mechanics of materials problem uses Axial elongation. Given axial load (P) = 37.0000 kip; length (L) = 99.0000 in; modulus (E) = 26,000 ksi; elongation (delta) = 0.1275 in, determine the area (A) in in².
Given
Find
area (A), in in²
Start with the thinking
- The governing relation printed in this handbook section is Axial elongation.
- Everything except A is given, so isolate A symbolically first — never rearrange after the numbers are in.
- Tabulate each given with its unit and confirm the units are consistent with the relation before substituting.
- Mechanics of Materials items reward recognising the unknown before touching a calculator.
Step-by-step solution
Step 1 — State the governing relation:
Step 2 — Rearrange the relation so that A stands alone on the left-hand side.
Step 3 — List the givens: axial load (P) = 37.0000 kip, length (L) = 99.0000 in, modulus (E) = 26,000 ksi, elongation (delta) = 0.1275 in.
Step 4 — Substitute the given values into the rearranged relation.
Step 5 — Evaluate:
Step 6 — Check: returning A = 1.1050 in² to
reproduces the given quantities, and both sides carry the same units.
Why the other options are there
- 2.2100 — kept a factor of two that cancels in the correct rearrangement.
- 0.5525 — dropped that same factor in the other direction.
- 1.2155 — rounded an intermediate value before the final step.
Reference: FE Reference Handbook — Mechanics of Materials → Thermal Deformations
A mechanics of materials problem uses Axial elongation. Given axial load (P) = 26.0000 kip; area (A) = 2.1000 in²; modulus (E) = 20,000 ksi; elongation (delta) = 0.5204 in, determine the length (L) in in.
Given
Find
length (L), in in
Start with the thinking
- The governing relation printed in this handbook section is Axial elongation.
- Everything except L is given, so isolate L symbolically first — never rearrange after the numbers are in.
- Tabulate each given with its unit and confirm the units are consistent with the relation before substituting.
- Mechanics of Materials items reward recognising the unknown before touching a calculator.
Step-by-step solution
Step 1 — State the governing relation:
Step 2 — Rearrange the relation so that L stands alone on the left-hand side.
Step 3 — List the givens: axial load (P) = 26.0000 kip, area (A) = 2.1000 in², modulus (E) = 20,000 ksi, elongation (delta) = 0.5204 in.
Step 4 — Substitute the given values into the rearranged relation.
Step 5 — Evaluate:
Step 6 — Check: returning L = 840.6 in to
reproduces the given quantities, and both sides carry the same units.
Why the other options are there
- 1,681 — kept a factor of two that cancels in the correct rearrangement.
- 420.3 — dropped that same factor in the other direction.
- 924.7 — rounded an intermediate value before the final step.
Reference: FE Reference Handbook — Mechanics of Materials → Thermal Deformations
A mechanics of materials problem uses Axial elongation. Given axial load (P) = 80.0000 kip; length (L) = 191.0 in; area (A) = 7.2000 in²; modulus (E) = 27,000 ksi, determine the elongation (delta) in in.
Given
Find
elongation (delta), in in
Start with the thinking
- The governing relation printed in this handbook section is Axial elongation.
- Everything except delta is given, so isolate delta symbolically first — never rearrange after the numbers are in.
- Tabulate each given with its unit and confirm the units are consistent with the relation before substituting.
- Mechanics of Materials items reward recognising the unknown before touching a calculator.
Step-by-step solution
Step 1 — State the governing relation:
Step 2 — Rearrange the relation so that delta stands alone on the left-hand side.
Step 3 — List the givens: axial load (P) = 80.0000 kip, length (L) = 191.0 in, area (A) = 7.2000 in², modulus (E) = 27,000 ksi.
Step 4 — Substitute the given values into the rearranged relation.
Step 5 — Evaluate:
Step 6 — Check: returning delta = 0.0786 in to
reproduces the given quantities, and both sides carry the same units.
Why the other options are there
- 0.1572 — kept a factor of two that cancels in the correct rearrangement.
- 0.0393 — dropped that same factor in the other direction.
- 0.0865 — rounded an intermediate value before the final step.
Reference: FE Reference Handbook — Mechanics of Materials → Thermal Deformations
A mechanics of materials problem uses Axial elongation. Given length (L) = 181.0 in; area (A) = 6.9000 in²; modulus (E) = 27,000 ksi; elongation (delta) = 0.2371 in, determine the axial load (P) in kip.
Given
Find
axial load (P), in kip
Start with the thinking
- The governing relation printed in this handbook section is Axial elongation.
- Everything except P is given, so isolate P symbolically first — never rearrange after the numbers are in.
- Tabulate each given with its unit and confirm the units are consistent with the relation before substituting.
- Mechanics of Materials items reward recognising the unknown before touching a calculator.
Step-by-step solution
Step 1 — State the governing relation:
Step 2 — Rearrange the relation so that P stands alone on the left-hand side.
Step 3 — List the givens: length (L) = 181.0 in, area (A) = 6.9000 in², modulus (E) = 27,000 ksi, elongation (delta) = 0.2371 in.
Step 4 — Substitute the given values into the rearranged relation.
Step 5 — Evaluate:
Step 6 — Check: returning P = 244.0 kip to
reproduces the given quantities, and both sides carry the same units.
Why the other options are there
- 488.1 — kept a factor of two that cancels in the correct rearrangement.
- 122.0 — dropped that same factor in the other direction.
- 268.4 — rounded an intermediate value before the final step.
Reference: FE Reference Handbook — Mechanics of Materials → Thermal Deformations
A mechanics of materials problem uses Axial elongation. Given axial load (P) = 51.0000 kip; length (L) = 82.0000 in; modulus (E) = 10,000 ksi; elongation (delta) = 0.2376 in, determine the area (A) in in².
Given
Find
area (A), in in²
Start with the thinking
- The governing relation printed in this handbook section is Axial elongation.
- Everything except A is given, so isolate A symbolically first — never rearrange after the numbers are in.
- Tabulate each given with its unit and confirm the units are consistent with the relation before substituting.
- Mechanics of Materials items reward recognising the unknown before touching a calculator.
Step-by-step solution
Step 1 — State the governing relation:
Step 2 — Rearrange the relation so that A stands alone on the left-hand side.
Step 3 — List the givens: axial load (P) = 51.0000 kip, length (L) = 82.0000 in, modulus (E) = 10,000 ksi, elongation (delta) = 0.2376 in.
Step 4 — Substitute the given values into the rearranged relation.
Step 5 — Evaluate:
Step 6 — Check: returning A = 1.7601 in² to
reproduces the given quantities, and both sides carry the same units.
Why the other options are there
- 3.5202 — kept a factor of two that cancels in the correct rearrangement.
- 0.8801 — dropped that same factor in the other direction.
- 1.9361 — rounded an intermediate value before the final step.
Reference: FE Reference Handbook — Mechanics of Materials → Thermal Deformations
A mechanics of materials problem uses Axial elongation. Given axial load (P) = 46.0000 kip; area (A) = 3.8000 in²; modulus (E) = 21,000 ksi; elongation (delta) = 0.0527 in, determine the length (L) in in.
Given
Find
length (L), in in
Start with the thinking
- The governing relation printed in this handbook section is Axial elongation.
- Everything except L is given, so isolate L symbolically first — never rearrange after the numbers are in.
- Tabulate each given with its unit and confirm the units are consistent with the relation before substituting.
- Mechanics of Materials items reward recognising the unknown before touching a calculator.
Step-by-step solution
Step 1 — State the governing relation:
Step 2 — Rearrange the relation so that L stands alone on the left-hand side.
Step 3 — List the givens: axial load (P) = 46.0000 kip, area (A) = 3.8000 in², modulus (E) = 21,000 ksi, elongation (delta) = 0.0527 in.
Step 4 — Substitute the given values into the rearranged relation.
Step 5 — Evaluate:
Step 6 — Check: returning L = 91.4230 in to
reproduces the given quantities, and both sides carry the same units.
Why the other options are there
- 182.8 — kept a factor of two that cancels in the correct rearrangement.
- 45.7115 — dropped that same factor in the other direction.
- 100.6 — rounded an intermediate value before the final step.
Reference: FE Reference Handbook — Mechanics of Materials → Thermal Deformations
A mechanics of materials problem uses Axial elongation. Given axial load (P) = 95.0000 kip; length (L) = 224.0 in; area (A) = 9.3000 in²; modulus (E) = 21,000 ksi, determine the elongation (delta) in in.
Given
Find
elongation (delta), in in
Start with the thinking
- The governing relation printed in this handbook section is Axial elongation.
- Everything except delta is given, so isolate delta symbolically first — never rearrange after the numbers are in.
- Tabulate each given with its unit and confirm the units are consistent with the relation before substituting.
- Mechanics of Materials items reward recognising the unknown before touching a calculator.
Step-by-step solution
Step 1 — State the governing relation:
Step 2 — Rearrange the relation so that delta stands alone on the left-hand side.
Step 3 — List the givens: axial load (P) = 95.0000 kip, length (L) = 224.0 in, area (A) = 9.3000 in², modulus (E) = 21,000 ksi.
Step 4 — Substitute the given values into the rearranged relation.
Step 5 — Evaluate:
Step 6 — Check: returning delta = 0.1090 in to
reproduces the given quantities, and both sides carry the same units.
Why the other options are there
- 0.2179 — kept a factor of two that cancels in the correct rearrangement.
- 0.0545 — dropped that same factor in the other direction.
- 0.1199 — rounded an intermediate value before the final step.
Reference: FE Reference Handbook — Mechanics of Materials → Thermal Deformations
A mechanics of materials problem uses Axial elongation. Given length (L) = 34.0000 in; area (A) = 8.2000 in²; modulus (E) = 13,000 ksi; elongation (delta) = 0.7367 in, determine the axial load (P) in kip.
Given
Find
axial load (P), in kip
Start with the thinking
- The governing relation printed in this handbook section is Axial elongation.
- Everything except P is given, so isolate P symbolically first — never rearrange after the numbers are in.
- Tabulate each given with its unit and confirm the units are consistent with the relation before substituting.
- Mechanics of Materials items reward recognising the unknown before touching a calculator.
Step-by-step solution
Step 1 — State the governing relation:
Step 2 — Rearrange the relation so that P stands alone on the left-hand side.
Step 3 — List the givens: length (L) = 34.0000 in, area (A) = 8.2000 in², modulus (E) = 13,000 ksi, elongation (delta) = 0.7367 in.
Step 4 — Substitute the given values into the rearranged relation.
Step 5 — Evaluate:
Step 6 — Check: returning P = 2,310 kip to
reproduces the given quantities, and both sides carry the same units.
Why the other options are there
- 4,620 — kept a factor of two that cancels in the correct rearrangement.
- 1,155 — dropped that same factor in the other direction.
- 2,541 — rounded an intermediate value before the final step.
Reference: FE Reference Handbook — Mechanics of Materials → Thermal Deformations