Question

The rectangular beam 'a' has length l, width b and depth

d. another beam 'b' has the same length and depth but width is double that of 'a'. the elastic strength of beam 'b' will be __________ as compared to beam a

Answer 1

Given:

The rectangular beam 'a':

length = l

width = b

depth = d

The rectangular beam 'b':

length = l

width = 2b

depth = d

To find:

The elastic strength of beam 'b' will be __________ as compared to beam 'a'

Solution:

Z = I/Y = (bd³/12) / (d/2) = bd²/6

Za = bd²/6

Zb = (2b)d²/6 = 2 bd²/6

Za/Zb = 1/2

Zb = 2Za

The elastic strength of beam 'b' will be twice as compared to beam 'a'.