(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

A winding engine lowers a load of 5 tonne at the rate of 1.4m/s2 for a distance of 10m. Assuming that the load is suspended from a steel rope 12mm in diameter calculate the stress and the extension in the rope after travelling this distance. Assume Esteel=200 GN/m2 and g=10m/s2

2. Relevant equations

I've used the following equations to base my answer around:-

Stress=Force/Area

Strain=extension/original length

E=Stress/Strain

3. The attempt at a solution

My attempt to answer this is as follows::surprised

A=3.142 * (6)^2

= 113.1mm2

= 113.1*10^-6 m2

F=5*1000*g where g=10m/s2

= 5*10^4

S=F/A = (5*10^4)/(113.1*10^-6)

Stress=442 MN/m2

using:- E=stress/strain

E= 200 GN/m2

strain=(442*10^6)/(200*10^9)

strain= 2.21*10^-3

My main query is where on earth does the 1.4m/s2 come into the answer and am I anywhere near the correct solution? This has been bugging me for quite some time now so any help would be much appreciated

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# Stress and extension question

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