A weight of 10kN falls by 30mm on a collar rigidly attached to a vertical bar 4m long and 1000mm² in section. What will be the instantaneous stress (E=210GPa)?

A weight of 10kN falls by 30mm on a collar rigidly attached to a verti

1.	A weight of 10kN falls by 30mm on a collar rigidly attached to a vertical bar 4m long and 1000mm² in section. What will be the instantaneous stress (E=210GPa)?
A.	149.4 N/mm²
B.	179.24 N/mm²
C.	187.7 N/mm²
D.	156.1 N/mm²
Answer» D. 156.1 N/mm²