Fundamentals of Engineering Statics and Dynamics 2 — Questions and Answers
Question 1: A 1,000 kg car accelerates from 0 to 20 m/s in 10 seconds. What is the net force acting on the car?
- 2,000 N (Correct answer)
- 20,000 N
- 200 N
- 1,000 N
Correct answer: 2,000 N
Acceleration a = Δv/Δt = 20/10 = 2 m/s². Net force F = ma = 1,000 × 2 = 2,000 N.
Question 2: What is the coefficient of static friction if a 100 N horizontal force just barely moves a 200 N block on a flat surface?
- 0.5 (Correct answer)
- 2.0
- 0.25
- 1.0
Correct answer: 0.5
At the point of impending motion, F = μₛN, so μₛ = F/N = 100/200 = 0.5.
Question 3: In truss analysis, which method involves cutting through the truss and applying equilibrium to a free body diagram of one part?
- Method of sections (Correct answer)
- Method of joints
- Finite element method
- Castigliano's method
Correct answer: Method of sections
The method of sections cuts the truss into two parts to find member forces directly using equilibrium equations.
Question 4: What is the work-energy theorem in dynamics?
- The net work done on a body equals the change in its kinetic energy (Correct answer)
- Work equals force times time
- Energy is always conserved in friction systems
- Work equals mass times velocity
Correct answer: The net work done on a body equals the change in its kinetic energy
The work-energy theorem states W_net = ΔKE = ½mv₂² - ½mv₁², relating net work to kinetic energy change.
Question 5: What type of force acts along a two-force member in a truss?
- Pure axial (tension or compression) force only (Correct answer)
- Shear force
- Bending moment
- Torsional force
Correct answer: Pure axial (tension or compression) force only
A two-force member has forces applied only at two points, resulting in pure axial load with no shear or bending.
Question 6: A wheel rolls without slipping. If the center moves at velocity v, what is the velocity of the contact point?
- Zero (Correct answer)
- v
- 2v
- v/2
Correct answer: Zero
For rolling without slipping, the instantaneous velocity at the contact point is zero (instantaneous center of rotation).
Fundamentals of Engineering Statics and Dynamics 2
A 1,000 kg car accelerates from 0 to 20 m/s in 10 seconds.
What is the net force acting on the car?