Read Rotating Rods: Integrate the Internal Tension
This short read prepares one exact NSEP pattern: stretch of a rotating rod. Identify the physical condition before calculating.
Chemistry questions first require the material, particles or reaction condition to be identified before a formula or rule is selected.
Start with the physical model
Read the configuration once, state the conserved quantity or governing law, and mark any changing geometry, sign convention or limiting condition.
Build the relation
At a section a distance x from the axis, the tension supports the centripetal force of the part from x to L: T(x)=∫x L ρAω2s ds = (ρAω2/2)(L2-x2).
Check before selecting
Check units, sign and one limiting case. A valid result must still fit the original geometry and stated constraint.
OlympIQ exam lens
- ✓Name the governing law before using a formula.
- ✓Keep the stated geometry and direction information explicit.
- ✓Use one unit or limiting-case check.
The tension is largest near the axle and is not constant along the rod.
Ready to try the pattern?
100% coverage across the linked question.
Practise the linked question