Question

a hollow cast iron column has internal diameter 200mm. what should be external diameter of the column. so that it could carry a load of 1600kn without the stress exceeding 90Mpa​

Answer 1

Explanation:

Here breaking stress ,σ=

A

F

=

π(R

2

−r

2

)

F

where r is the internal radius and R be the external radius.

Now, R

2

−r

2

=

πσ

F

R

2

=

πσ

F

+r

2

=

3.14×90×10

6

1.6×10

6

+(0.1)

2

=0.0156

R=0.125 m=125 mm

Thus minimum external diameter is 2R=2(125)=250 mm=0.250 m=0 ; (It is 0 in nearest integer)