Question

To appreciate the strength of gravity, calculate the number of steel cables that would be required, in the absence of gravity, to hold the Moon in orbit about the Earth. Each cable has a cross-sectional area of 1 square meter, and the tensile strength of steel is 370 MPa.

Answer 1

Answer:

$N=5.36*10^{17}$

Explanation:

From the question we are told that:

Tensile strength of steel $\sigma_c=370 MPa.=370*10^6$

Cross-sectional area $A= 1m^2$

Generally the equation for Total Force is mathematically given by

 $F = \frac{G M m}{r^2}$

 $F=\frac{6.67*10^{-11}*7.35*10^{22}*5.97*10^{24}}{(384*10^3)^2}$

Since this is the force of each cable

 $F=\sigma_c NA$

 $F= 370*10^6*N*1$

Therefore

 $370*10^6*N*1=\frac{6.67*10^{-11}*7.35*10^{22}*5.97*10^{24}}{(384*10^3)^2}$

 $N=5.36*10^{17}$