Section B: Static Engineerig Systems

Question 1

SOHCAHTOA

Answer 1

O A O

S H C H T A

Question 2

Taking moments equation

Answer 2

M = Fd

F - force
d - moment arm

Question 3

Worked example

Answer 3

Using the diagram below, find the magnitude, direction, position and equilibrant of the resultant
force.
Mass = 1kg
FW = Force due to the weight F = 3N

• missing the diagram *

Draw a sketch of the problem ❑Resolve any forces that are acting at an angle
❑Add up all the forces in the x direction to find Rx
❑Add up all the forces in the y direction to find Ry
❑Find the magnitude (size) of the resultant force
❑Find the angle of the resultant force ❑Take moments about any point ❑Find the position of the resultant force

Question 4

Reactions forces

Answer 4

F =0 x
F =0 y
And,the moments must bebalanced:
R+R=F 12
M=M clockwise
anti−clockwise

Question 5

Overall force

Answer 5

(N/m) x length = force

Question 6

Stress, strain and young’s modules

Answer 6

.

Question 7

Stress equation

Answer 7

stress( ) = Force / Area

Question 8

Strain equation

Answer 8

strain( ) = (change in length) / Length

Question 9

Young’s modulus equation

Answer 9

Young’s Modulus(E) = stress / strain

Question 10

Shear stress equation

Answer 10

Stress = Force/Area

Question 11

(Shear stress) stress equation

Answer 11

𝑠𝑡𝑟𝑒𝑠𝑠 𝜏 =

𝐹𝑜𝑟𝑐𝑒 / 𝐴𝑟𝑒𝑎 = 100 / 1 = 100𝑁/𝑚2

Question 12

(Shear strain) strain equation

Answer 12

𝑠𝑡𝑟𝑎𝑖𝑛 𝛾 = (change in length) / length

Question 13

(Shear) Modulus of rigidity equation

Answer 13

𝑀𝑜𝑑𝑢𝑙𝑢𝑠 𝑜𝑓 𝑟𝑖𝑔𝑖𝑑𝑖𝑡𝑦 𝐺 = 𝜏 / 𝛾