A seamless pipe of diameter d m is to carry fluid under a pressure of p kN/cm2. The necessary thickness t of metal in cm, if the maximum stress is not to exceed σ kN/cm2 is
1
\(t \ge \frac {pd}{2\sigma} \ cm\)
2
\(t \ge \frac {100pd}{2\sigma} \ cm\)
3
\(t \le \frac {pd}{2\sigma} \ cm\)
4
\(t \le \frac {100pd}{2\sigma} \ cm\)
5
\(t \ge \frac {10pd}{2\sigma} \ cm\)