# Physics mechanics question: find the instantaneous elongation and stress in the bar

A mass of 336 kg falls through a distance of 17.5mm on to the stop at the lower end of a vertical steel bar which is 5.2 metres long and 735 square mm in cross section area. If the modulus of elasticity is equal to 210 GPascals for the bar, find

a) instantaneous elongation

b) the stress in the bar

Please provide detailed step by step solution that is readable.

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#### Solution Preview

Mass of the falling body m = 336 kg

Distance of free fall h = 17.5 mm = 17.5/1000 m

Length of the bar l = 5.2 m

Area of cross-section of the bar A= 735 square mm = 735*10^(-6) sq. m

Mod of ...

#### Solution Summary

With good explanations and calculations, the problem is solved. The expert finds the instantaneous elongation in the bar.

$2.19