Force
Statics · FE Reference Handbook section
Handbook notes for this section
Definitions and conditions exactly as the handbook states them.
- The vector form of a force is
Core formulas for this FE topic
Definitions, applicability, units, assumptions and worked examples for each relation.
Worked exam-style examples
The four ways this section is written on the real exam — thoughts first, then equations, then substitution.
Two forces act at a gusset plate: 44 kN at 22° and 81 kN at 139° from the positive x-axis. Resolve each force into components and determine the magnitude and direction of the resultant force.
Given
Find
Resultant force magnitude R and its direction
Start with the thinking
- A force system is resolved by summing x- and y-components separately.
- The resultant of concurrent forces is the vector sum, never the arithmetic sum of magnitudes.
Step-by-step solution
Formula
F₁ components
F₂ components
Sums — ΣFₓ = -20.34 kN, ΣF_y = 69.62 kN
Formula — R = √(ΣFₓ² + ΣF_y²)
Substituting
Why the other options are there
- 125 kN (magnitudes added)
- 20.34 kN (y-component dropped)
Reference: FE Reference Handbook — Statics → Force
Two forces act at a gusset plate: 69 kN at 20° and 83 kN at 130° from the positive x-axis. Resolve each force into components and determine the magnitude and direction of the resultant force.
Given
Find
Resultant force magnitude R and its direction
Start with the thinking
- A force system is resolved by summing x- and y-components separately.
- The resultant of concurrent forces is the vector sum, never the arithmetic sum of magnitudes.
Step-by-step solution
Formula
F₁ components
F₂ components
Sums — ΣFₓ = 11.49 kN, ΣF_y = 87.18 kN
Formula — R = √(ΣFₓ² + ΣF_y²)
Substituting
Why the other options are there
- 152 kN (magnitudes added)
- 11.49 kN (y-component dropped)
Reference: FE Reference Handbook — Statics → Force
Two forces act at a gusset plate: 26 kN at 49° and 46 kN at 163° from the positive x-axis. Resolve each force into components and determine the magnitude and direction of the resultant force.
Given
Find
Resultant force magnitude R and its direction
Start with the thinking
- A force system is resolved by summing x- and y-components separately.
- The resultant of concurrent forces is the vector sum, never the arithmetic sum of magnitudes.
Step-by-step solution
Formula
F₁ components
F₂ components
Sums — ΣFₓ = -26.93 kN, ΣF_y = 33.07 kN
Formula — R = √(ΣFₓ² + ΣF_y²)
Substituting
Why the other options are there
- 72 kN (magnitudes added)
- 26.93 kN (y-component dropped)
Reference: FE Reference Handbook — Statics → Force
Two forces act at a gusset plate: 47 kN at 53° and 53 kN at 120° from the positive x-axis. Resolve each force into components and determine the magnitude and direction of the resultant force.
Given
Find
Resultant force magnitude R and its direction
Start with the thinking
- A force system is resolved by summing x- and y-components separately.
- The resultant of concurrent forces is the vector sum, never the arithmetic sum of magnitudes.
Step-by-step solution
Formula
F₁ components
F₂ components
Sums — ΣFₓ = 1.79 kN, ΣF_y = 83.44 kN
Formula — R = √(ΣFₓ² + ΣF_y²)
Substituting
Why the other options are there
- 100 kN (magnitudes added)
- 1.79 kN (y-component dropped)
Reference: FE Reference Handbook — Statics → Force
Two forces act at a gusset plate: 71 kN at 50° and 40 kN at 118° from the positive x-axis. Resolve each force into components and determine the magnitude and direction of the resultant force.
Given
Find
Resultant force magnitude R and its direction
Start with the thinking
- A force system is resolved by summing x- and y-components separately.
- The resultant of concurrent forces is the vector sum, never the arithmetic sum of magnitudes.
Step-by-step solution
Formula
F₁ components
F₂ components
Sums — ΣFₓ = 26.86 kN, ΣF_y = 89.71 kN
Formula — R = √(ΣFₓ² + ΣF_y²)
Substituting
Why the other options are there
- 111 kN (magnitudes added)
- 26.86 kN (y-component dropped)
Reference: FE Reference Handbook — Statics → Force
Two forces act at a gusset plate: 63 kN at 71° and 69 kN at 122° from the positive x-axis. Resolve each force into components and determine the magnitude and direction of the resultant force.
Given
Find
Resultant force magnitude R and its direction
Start with the thinking
- A force system is resolved by summing x- and y-components separately.
- The resultant of concurrent forces is the vector sum, never the arithmetic sum of magnitudes.
Step-by-step solution
Formula
F₁ components
F₂ components
Sums — ΣFₓ = -16.05 kN, ΣF_y = 118.1 kN
Formula — R = √(ΣFₓ² + ΣF_y²)
Substituting
Why the other options are there
- 132 kN (magnitudes added)
- 16.05 kN (y-component dropped)
Reference: FE Reference Handbook — Statics → Force
Two forces act at a gusset plate: 71 kN at 20° and 68 kN at 141° from the positive x-axis. Resolve each force into components and determine the magnitude and direction of the resultant force.
Given
Find
Resultant force magnitude R and its direction
Start with the thinking
- A force system is resolved by summing x- and y-components separately.
- The resultant of concurrent forces is the vector sum, never the arithmetic sum of magnitudes.
Step-by-step solution
Formula
F₁ components
F₂ components
Sums — ΣFₓ = 13.87 kN, ΣF_y = 67.08 kN
Formula — R = √(ΣFₓ² + ΣF_y²)
Substituting
Why the other options are there
- 139 kN (magnitudes added)
- 13.87 kN (y-component dropped)
Reference: FE Reference Handbook — Statics → Force
Two forces act at a gusset plate: 43 kN at 17° and 90 kN at 135° from the positive x-axis. Resolve each force into components and determine the magnitude and direction of the resultant force.
Given
Find
Resultant force magnitude R and its direction
Start with the thinking
- A force system is resolved by summing x- and y-components separately.
- The resultant of concurrent forces is the vector sum, never the arithmetic sum of magnitudes.
Step-by-step solution
Formula
F₁ components
F₂ components
Sums — ΣFₓ = -22.52 kN, ΣF_y = 76.21 kN
Formula — R = √(ΣFₓ² + ΣF_y²)
Substituting
Why the other options are there
- 133 kN (magnitudes added)
- 22.52 kN (y-component dropped)
Reference: FE Reference Handbook — Statics → Force
Two forces act at a gusset plate: 43 kN at 64° and 83 kN at 123° from the positive x-axis. Resolve each force into components and determine the magnitude and direction of the resultant force.
Given
Find
Resultant force magnitude R and its direction
Start with the thinking
- A force system is resolved by summing x- and y-components separately.
- The resultant of concurrent forces is the vector sum, never the arithmetic sum of magnitudes.
Step-by-step solution
Formula
F₁ components
F₂ components
Sums — ΣFₓ = -26.36 kN, ΣF_y = 108.3 kN
Formula — R = √(ΣFₓ² + ΣF_y²)
Substituting
Why the other options are there
- 126 kN (magnitudes added)
- 26.36 kN (y-component dropped)
Reference: FE Reference Handbook — Statics → Force
Two forces act at a gusset plate: 20 kN at 70° and 21 kN at 135° from the positive x-axis. Resolve each force into components and determine the magnitude and direction of the resultant force.
Given
Find
Resultant force magnitude R and its direction
Start with the thinking
- A force system is resolved by summing x- and y-components separately.
- The resultant of concurrent forces is the vector sum, never the arithmetic sum of magnitudes.
Step-by-step solution
Formula
F₁ components
F₂ components
Sums — ΣFₓ = -8.01 kN, ΣF_y = 33.64 kN
Formula — R = √(ΣFₓ² + ΣF_y²)
Substituting
Why the other options are there
- 41 kN (magnitudes added)
- 8.01 kN (y-component dropped)
Reference: FE Reference Handbook — Statics → Force