# How much does cable stretch?

**1. The problem statement, all variables and given/known data**

A 1.25m diameter wrecking ball hangs motionless from a 1.75 cm diameter cable. The wrecking ball is solid and is constructed of steel (density = 7800 kg/m3). If the cable is 16 m long, how much does the cable stretch? For the cable use E = 175 GPa.

**2. Relevant equations**

δ=(FL/AE)

**3. The attempt at a solution**

δ=(FL/AE)

F=ρ*v*g

=7800*(4/3)*pi*r^3*9.8

=78171.66 N

A=PI*R*R

=(pi*(1.75*1.75)/4)*10^-4

=2.4*10^-4

E=175000 N-m^2

L=16 m

When I plug in the values I get 29779.68 m which I know cannot be correct.

Thanks for your time

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