Engineering Sciences Flashcards

What is Newton's second law of motion?

Answer: F = ma (force equals mass times acceleration)

Newton's second law states that the net force acting on an object equals its mass multiplied by its acceleration (F = ma), forming the foundation of dynamics.

The coefficient of thermal expansion is a measure of:

Answer: How much a material expands per degree of temperature change

The coefficient of thermal expansion (α) quantifies the fractional change in length, area, or volume per unit temperature change, critical for designing structures in Saudi Arabia's extreme temperatures.

Hooke's Law states that stress is proportional to strain within the:

Answer: Elastic limit

Hooke's Law (σ = Eε) applies only within the elastic region where deformation is reversible. Beyond the elastic limit, permanent plastic deformation occurs.

The first law of thermodynamics is a statement of:

Answer: Conservation of energy

The first law states that energy cannot be created or destroyed, only converted between forms. For a closed system, ΔU = Q - W (internal energy change equals heat added minus work done).

Young's modulus is defined as the ratio of:

Answer: Stress to strain in the elastic region

Young's modulus (E) = stress/strain = (F/A)/(ΔL/L) in the elastic region. It measures a material's stiffness. Steel has E ≈ 200 GPa, concrete ≈ 25-30 GPa.

In fluid mechanics, Reynolds number determines:

Answer: Whether flow is laminar or turbulent

Reynolds number (Re = ρvD/μ) is a dimensionless ratio of inertial to viscous forces. Re 4000 indicates turbulent flow in pipes.