How many members can a truss with 7 joints have and still be considered statically determinate?

Question:

If a truss has 7 joints, how many members can the truss have and still be considered statically determinate?

Group of answer choices:

5

11

14

Varies on the type of truss (Howe, Pratt, etc.)

9

Answer:

The truss with 7 joints can have a maximum of 11 members and still be considered statically determinate.

In structural engineering, a truss is considered statically determinate if the number of members in it does not exceed a certain limit based on the number of joints. The formula to determine this limit is M ≤ 2J - 3, where M is the number of members and J is the number of joints.

For a truss with 7 joints, the maximum number of members it can have is calculated as 2 x 7 - 3 = 14 - 3 = 11 members. Any number of members beyond 11 will render the truss statically indeterminate due to the presence of redundant members that cannot be supported by the given joints.

Therefore, in this case, the truss with 7 joints can have up to 11 members and still be statically determinate.