Overview
This lecture explains the concepts of statics and dynamics in engineering mechanics, detailing their definitions, importance, and subdivisions.
Equilibrium
- Equilibrium means a body is either at rest or moving with constant velocity (zero acceleration).
- A body in equilibrium experiences zero net force and zero net torque.
- Equilibrium is necessary for analyzing systems in statics.
Statics
- Statics studies forces and their effects on bodies in equilibrium (at rest or constant velocity).
- The branch of engineering mechanics focused on equilibrium situations is called statics.
- Applications include determining load capacity of bridges, force on dams, weight cranes can lift, and stationary cable forces.
Dynamics
- Dynamics deals with forces and their effects on bodies in motion (not in equilibrium).
- Dynamics helps analyze movement, such as the path of a thrown stone or a jet's flight.
- Used for design against earthquakes and for calculating the force needed to launch satellites.
Branches of Dynamics
- Kinematics analyzes the motion of bodies without considering the forces causing the motion.
- Kinetics examines the forces acting on bodies, without focusing on the resulting motion.
Tools for Statics and Dynamics
- Solving statics and dynamics problems requires knowledge of Newton's laws of motion.
- Vector algebra is essential because quantities like force and velocity are vectors.
Key Terms & Definitions
- Equilibrium — State where a body’s net force and net torque are zero.
- Statics — Study of forces on bodies in equilibrium.
- Dynamics — Study of forces on bodies in motion.
- Kinematics — Study of motion without regard to its causes.
- Kinetics — Study of forces causing motion.
- Vector Algebra — Mathematical approach to handle physical quantities with both magnitude and direction.
Action Items / Next Steps
- Review Newton's laws of motion.
- Study basic concepts of vector algebra.