First slide
Elastic Modulie
Question

Two blocks of masses 1 kg and 2kg are connected by a metal wire going over a smooth pulley as shown. The breaking stress of the metal is \large \frac {40}{3\pi}\times 10^6Nm^{-2}. If g = 10ms–2. Then what should be the minimum radius of the wire used if it is not to break?

Moderate
Solution

\large T = \frac{{2{m_1}{m_2}g}}{{{m_1} + {m_2}}};\;f = T = \frac{{2 \times 1 \times 20}}{{2 + 1}} = \frac{{40}}{3}N
\large S = \frac{F}{A} = \frac{T}{{\pi {r^2}}} \Rightarrow \frac{{40}}{{3\pi }} \times {10^6} = \frac{{40}}{{3\pi {r^2}}}
\large {r^2} = {10^{ - 6}};\;r = {10^{ - 3}};\;r = 1mm

Get Instant Solutions
When in doubt download our app. Now available Google Play Store- Doubts App
Download Now
Doubts App