Fundamentals of Engineering Flashcards

Which numerical method uses the formula x_{n+1} = x_n − f(x_n)/f'(x_n) to find roots?

Answer: Newton-Raphson method

The Newton-Raphson method iterates using the function and its derivative to converge to a root.

A projectile is launched at 30° above horizontal with an initial speed of 40 m/s. What is the horizontal range (g = 10 m/s²)?

Answer: 138.6 m

Range R = V₀²sin(2θ)/g = (40²)(sin60°)/10 = 1600(0.866)/10 ≈ 138.6 m.

In material science, ductile fracture is characterized by:

Answer: Significant plastic deformation and necking

Ductile fracture involves considerable plastic deformation, necking, and energy absorption before failure.

For a three-phase balanced Y-connected system, the relationship between line voltage (VL) and phase voltage (Vφ) is:

Answer: VL = √3 · Vφ

In a Y-connected system, line voltage leads phase voltage by 30° and VL = √3 · Vφ.

The net present worth method selects a project as acceptable when its NPW is:

Answer: Greater than or equal to zero

A project is economically acceptable if NPW ≥ 0, meaning benefits meet or exceed costs at the given MARR.

Which of the following statements about entropy is correct according to the Second Law of Thermodynamics?

Answer: Total entropy of an isolated system always increases or stays the same

The Second Law states that entropy of an isolated system always increases for irreversible processes and stays constant for reversible ones.

A truss joint has forces: 50 kN tension in member A (horizontal) and an unknown force in member B (vertical). If the joint is in equilibrium with no external load, what is the force in member B?

Answer: 0 kN (zero-force member)

Since no external force acts and member A is horizontal, member B carries zero force (zero-force member by inspection).