Question

A simple band brake is applied to drum of 560 mm diameter which rotates at 240 r.p.m angle of contact of the band is 270${}^{\circ }$. Coefficient of friction is 0.3. The power absorbed is 40 kW.


If the thickness of band is 3 mm and the tensile stress is limited to 40 MPa, then the width of the band is

• A. 87.4 mm
• B. 92.6 mm
• C. 62.6 mm
• D. 75.1 mm

Answer 1

The correct option is C 62.6 mm

${\sigma }_t=40MPa,t=3mm$

$\sigma \times w\times =7502$

$40\times w\times 3=7502$

$\Rightarrow w=62.5mm$