Laws of motion Flashcards
1st law
An object at rest tends to stay at rest and an object in motion tends to stay in motions at a constant speed along a straight-line path, unless an outside net force is placed upon it.
Inertia
Property of objects to resist changes in motion
Net force
When more than a single force acts on an object
Force
Push or pull
- gravitational, electrical, magnetic, muscular
- lbs and newtons
Vector quantity
A quantity such a as force that has both magnitude and direction
Mechanical equilibrium
When the net force on something is zero
- vector sum of forces equals zero
(Upward forces are + and downward forces are -)
Support force
Normal force
- upward force opposite to the force of gravity
Dynamic equilibrium
An object moving at a constant speed in a straight-line path is also in equilibrium
Equilibrium
State of no change (must be 2+ forces acting on object; cannot just be 1)
Linear motion
The simplest motion is the simplest form of motion (straight line path)
Speed =
Distance covered per unit of time
Speed = distance / time
Instantaneous speed
Speed at any instant in time
Average speed
Total distance covered / time interval
- does not indicate different speeds and variations that may take place during shorter time intervals
Velocity
Linear motion
- description of how fast and in what direction an object is moving
Vector quantity
Quantity that specifies direction as well as magnitude (such as velocity and force)
Constant velocity
Motion in a straight line at a constant speed
- must have constant speed and constant direction
Changing velocity
Either the speed or the direction (or both) change