Statics and Dynamics Flashcards

What is the moment of inertia of a solid cylinder (mass M, radius R) about its central axis?

Answer: ½MR²

The moment of inertia of a solid cylinder about its axis of symmetry is I = ½MR².

In projectile motion (neglecting air resistance), which component of velocity remains constant?

Answer: Horizontal component

With no air resistance, only gravity acts, and it acts vertically — so the horizontal velocity component remains constant throughout.

The coefficient of restitution e = 1 describes:

Answer: A perfectly elastic collision

A coefficient of restitution of 1 indicates a perfectly elastic collision where kinetic energy is fully conserved.

For a free-body diagram, which of the following should be included?

Answer: All external forces and moments acting on the body

A free-body diagram includes all external forces and moments acting on the isolated body, revealing what affects its motion.

What is the angular momentum of a 2 kg mass rotating at 5 rad/s with a radius of 0.4 m?

Answer: 1.6 kg·m²/s

L = Iω = mr²ω = 2 × (0.4)² × 5 = 2 × 0.16 × 5 = 1.6 kg·m²/s.

A truss member in compression will fail by which mechanism at long lengths?

Answer: Euler buckling

Slender compression members fail by Euler buckling — a sudden lateral deflection — before reaching the material's yield stress.