Explanation:
It is given that,
Mass of concrete pilling, m = 50 kg
Diameter of wire, d = 1 mm
Radius of wire, r = 0.0005 m
Length of wire, L = 11.2
Young modulus of steel, 
The young modulus of a wire is given by :





So, the wire will stretch 0.034 meters. Hence, this is the required solution.
Speed=Distance/Time
Distance=40m,time=5.79seconds
S=40/5.79
=6.908m/s
by an echo meter
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