Q: A rod built into the wall is loaded with $50$ N up$-$and$-$down. The radius of the rod is $2$ mm$.$ The length of the rod is $10$ mm$.$ After how many repetitions$($cycles$)$ the rod is started to damage?

$($The material tensile yield strength is $250$ MPa$)$Q: A rod built into the wall is loaded with $50N$ up$-$and$-$down. The radius of the rod is $2mm.$ The length of

the rod is $10mm.$ After how many repetitions$($cycles$)$ the rod is started to damage?

$($The material tensile yield strength is $250$MPa $)$