Physical Science Chapter 1: Motion

Natural Motion: Objects move in a predictable manner based on how they are manipulated.
Violent Motion: Results from external forces being applied to an object.

Distance: Measured in meters (m), approximately 39 inches.
Mass: Measured in grams (g); a nickel weighs about 3 grams.
Volume:
- Liquid volume: Measured in liters; slightly more than a quart.
- Solid volume: Measured in cubic centimeters (cm³); about the size of a sugar cube.
Metric Prefixes: Based on powers of 10; 1000 meters equals 1 kilometer (km).
Conversion: Metric units can convert between centimeters [cm] to meters [m], millimeters [mm] to kilometers [km].

Speed Formula: Speed equals distance divided by time (Speed = Distance/Time).
Units of Distance: Includes inches, feet (ft), miles, meters (m), kilometers (km), centimeters (cm), light-years.
Units of Time: Includes minutes (min), seconds (sec), hours (hr), years (yr).
Average Speed: Total distance travelled divided by total time taken.
Acceleration: The rate of change of speed or velocity over time.
- Positive acceleration indicates an increase in speed.
- Negative acceleration, or deceleration, indicates a decrease in speed.

Force: Defined as a push or pull acting on an object.
Balanced Forces: Forces that are equal in magnitude and opposite in direction, resulting in no motion.
Unbalanced Forces: Forces that cause an object to move.
Vector Representation: Visual arrows represent forces with both magnitude and direction; length indicates size and angle indicates direction.
Net Force: The sum of all forces acting on an object.

Frictional Force: Opposes relative motion between surfaces.
Static Friction: Present when a stationary object experiences an applied force; no movement occurs.
Kinetic Friction: Acts when an object is sliding or moving against another.
Normal Force: The support force exerted by a surface against the weight of an object resting on it.

Uniform Circular Motion: Consistent speed while changing direction as the object moves around a circle; acceleration points towards the circle’s center.
Linear Motion: Motion along a straight path.
Tangential Speed: The distance traveled by an object per unit time along a circular path.
Rotational Speed (Angular Speed): Number of rotations or revolutions per unit of time, measured in radians per second (rad/s).
Frequency: The number of complete rotations per unit time; measured in hertz (Hz), calculated with f = 1/T, where T is time period.

Energy: The capacity to perform work.
Kinetic Energy (KE): Energy possessed by an object in motion; calculated as KE = 1/2 mv² (mass times the square of velocity).
Potential Energy (PE): Energy stored due to an object's position; calculated as PE = mgh (mass times gravitational acceleration times height).
Work-Energy Theorem: The net work done by external forces equals the change in kinetic energy.
Total Mechanical Energy: The sum of kinetic energy and potential energy of an object.
Law of Conservation of Energy: Total energy in an isolated system remains constant; energy can change forms but is not destroyed.