Class notes Statics of Rigid Bodies (ES333)

ENGINEERING MECHANICS
STATICS OF RIGID BODIES
(3 Example Problems with 3 Practice Problems)



PART I:

RESULTANT OF CONCURRENT AND NON-CONCURRENT FORCE SYSTEM

, RESULTANT OF CONCURRENT AND NON-CONCURRENT FORCE
SYSTEM

Example Problem 1:
Study the figure shown and answer the following.

225 lbs
100 lbs




38° 45°


80°




80 lbs


a. Find the magnitude of the horizontal component of the resultant of the force system.
b. Find the resultant force of the force system.
c. Find the angle of the resultant force with respect to the horizontal axis.

Solution:

a. Horizontal component:

∑ 𝐹𝑋 = 225 𝑐𝑜𝑠45° − 100 𝑐𝑜𝑠38° − 80 𝑐𝑜𝑠80°


∑ 𝑭𝑿 = 𝟔𝟔. 𝟒𝟎𝟔𝟏 𝒍𝒃𝒔

b. Resultant force:

• Solve the magnitude of the vertical component.

∑ 𝐹𝑌 = 225 𝑠𝑖𝑛45° + 100 𝑠𝑖𝑛38° − 80 𝑠𝑖𝑛80°

∑ 𝐹𝑌 = 141.8806 𝑙𝑏𝑠