A spider of mass 6.4 10 -4 kg hangs from a 72.2-cm-long thread whose diameter is 2.0 10 -3 mm. Young’s modulus of thread is 3. 10 9 N/m 2 . By how

A spider of mass 6.4  10-4 kg hangs from a 72.2-cm-long thread whose diameter is 2.0  10-3mm. Young’s modulus of thread is 3.  109 N/m2. By how much does the thread stretch?

m?

Calculate the force a piano tuner applies to stretch a steel piano wire 7.00 mm, if the wire is originally 0.890 mm in diameter and 1.35 m long. Young’s modulus for steel is 210*109 N/m2.

N?