Stress And Strain

Strain is defined as: If a wire is stretched to double its original length:

The stress on the leg is related to the force applied and the area over which it is distribute(D) The force exerted by the man is proportional to his weight, which is proportional to his volume (since density remains constant). As the height of the man increases, his volume increases in proportion to the cube of the height (i.e., volume height ). Since stress is defined as force per unit area, and area (cross-sectional area of the leg) increases with the square of the height (i.e., area height ), we can find the factor by which stress changes: - Let the original height be . The new height is . - The volume will increase by a factor of . - The area will increase by a factor of . Therefore, the stress, which is proportional to force per unit area, will increase by a factor of: Thus, the stress will change by a factor of 4.