Question

In a flywheel, the value of safe stress is 25 MNm^-2 and density of material is 10000 kgm^-3. The maximum peripheral velocity will be
1. 200 ms^-1
2. 100 ms^-1
3. 50 ms^-1
4. 25 ms^-1

Answer 1

Correct Answer - Option 3 : 50 ms^-1

Concept:

Peripheral velocity is the speed at the periphery of a circular part due to its rotation. It is given by

v = \( { \sqrt{\frac {σ }{ρ }} }\)

Where σ = stress; ρ = density

Calculation:

Given:

σ = 25 MNm^-2 = 25 × 10⁶ Nm-2; ρ = 10000 kgm^-3

As the given stress is safe stress, so here we will get the maximum peripheral velocity.

v = \( { \sqrt{\frac {σ }{ρ }} }\)

v = \( { \sqrt{\frac {25\; × \;10^6 }{10000 }} }\)

v = 50 ms-1