To determine the average normal stress and strain in rod AB, we need to know the length and cross-sectional area of the rod, as well as the gravitational acceleration.
Let's assume that the length of rod AB is L meters and the cross-sectional area is A square meters. The gravitational acceleration is typically denoted as g and has a value of approximately 9.8 m/s^2.
The weight of the load can be calculated using the formula:
Weight = mass * gravitational acceleration
Weight = 75 kg * 9.8 m/s^2 = 735 N
The average normal stress can be calculated using the formula:
Average normal stress = Weight / cross-sectional area
Average normal stress = 735 N / A square meters
The average normal strain can be calculated using the formula:
Average normal strain = change in length / original length
Since the load is hanging vertically, the change in length is equal to the elongation of the rod due to the weight of the load. The elongation can be calculated using Hooke's Law:
Elongation = (Weight * L) / (cross-sectional area * Young's modulus)
Young's modulus is a material property that describes its stiffness. Without this information, we cannot calculate the average normal strain.
Therefore, we can calculate the average normal stress, but we need additional information to calculate the average normal strain.