Unit 1: Elementary Mechanics and Dynamics Flashcards
Force
may be defined as any action on a body that changes its size, shape, or state of rest/motion
Velocity
is the rate of change in position/displacement that occurs in a given time.
Force SI unit?
Newton
Scalar Quantity
Only contain magnitude. Examples of scalar quantities include time , volume , speed, mass , temperature , distance, entropy, energy , work ,
Vector Quantity
a quantity that has both magnitude and direction. Examples of vector quantities include displacement, velocity, position, force, and torque.
What is Work?
When force is applied to a body and it causes it to move a distance then work is done.
Work Formula
Work Done = Force in Newtons * Distance in meters
What is work measured in?
In joules
Power
Is the rate at which work is done in a given time.
Acceleration of Gravity
9.81 m/s^2
Space Diagrams
Illustrates a systems of vectors
Coplanar Vectors
If all vectors are in the same plane or quadrant they are coplanar
Concurrent Vectors
Simply vectors one after another
Resultant
A single vector that can represent a number of vectors displacement
Displacement Formula
D = Average Velocity * Time
Average Velocity
Avg V = Intial veloc
Static Frition
The resistance or friction to overcome required to start a body in motion
Kinetic Friction
The friction that must be overcome to keep a body in motion
Belt Drives
Moves mechanical energy between pulleys. If there is no slippage between the belt and pulleys the linear speed of any point on each pulley will be the same and equal to the linear speed of the belt.
If the driver is smaller the follower will rotate slower. The opposite is also true. A bigger driver will move a smaller follower faster
The tension of the bottom belt is always greater than the tension in the top belt.
Intermediate Gears
Do not affect speed of driven gears, they just transmit power
Tensile Stress
A bar or uniform cross-section is subjected to a pair of forces acting in different directions. Such as a pipe being stretched.
Compressive Stress
Forces being applied towards, or inwards on to a bar or plate.
Shear Stress
The stress experienced by a bolt or rivet holding two pieces of metal together. as the two metal pieces move or experience pull the bolt may break or sheer apart.
