Motion and Acceleration

Motion and Acceleration

1. What is motion?

   • Motion is the process and action of an object being physically moved by a force which results in distance increasing or decreasing. 

2. Are you in motion?

   • Refrence points are used  to determine whether or an object is in motion. 
   • How to determine a reference point
     • When picking a reference point,  make sure that the point itslef is not a moving object because, when you determine the distance it is travelling at, this will vary as both objects are moving. 
     • Examples of reference points:
       • Reference points can be anywhere around you, as long as it is not in motion itslef. Examples of refernce points could be as simple as trees, tables, buildings and many others aroung us. However there can be refrence points like the sun, stars, satelittles adn other objects in space. 
     • Relative Motion
       • This type of motion is used when you do choose a reference point that is moving such as the earth and satellites in space. 

3. What is speed?

   • Speed is a type of rate that tells you the amount of something that occurs or changes over units of time.  Speed= distance divided by time
   • Average Speed
     • When the speed of an object is not constant. Average speed is calcualted by dividing the total distance traveled by the total time. 
   • Instantaneous Speed
     • When there is a set amount of time and distance you are given to calculate. Instantaneous speed can be calculated by simply finding the speed it was at, at a specific time and place. 
   • Velocity
     • When both the direction and speed of an objects' motion is given. Speed in a given direction (i.e. north, east, south, west)

4. How can you measure distance?

   • When measuring distance, you can use units, or standard quantities of measurements. i.e. cups, miles, meters etc. 
   • System of measuring?
     • Scientists use the International System of Units when describing motion and the distance an object moves. 
     • Examples:
       • Centimeter (cm) - "Centi" which means "one hundredth"  Millimeter (mm) - "Milli" which means one thousandth"  Kilometers (km) - "Kilo" which means "one thousand"

5. Acceleration

   • The rate at which velocity changes. In science, this refers to increasing speed, decreasing speed or changing direction. 
   • Incresing Speed
     • When the object accelerates. i.e. when a ball is being thrown. 
   • Decresing speed
     • When an object slows down, the change in speed is called deceleration or negative acceleration. i.e. when a car slows down at a signal. 
   • Changing direction
     • When an object accelerates when going in a direction let it be curvy, windy and others. i.e. when a baseball is hit towards a different direction. Objects can continuously change direction without changing it's speed. This is circular motion i.e. a Ferris wheel                       
     • Calculating acceleration
       • Determining:
         • Calculate the change in speed per unit of time.  Acceleration = Final speed - Initial speed divided by time. 
       • Graphing acceleration
         • Speed versus time graph to analyze the motion of an accelerating object 
         • Speed versus time graph
           • If the line slants upward, then you are moving at a very high speed. If the line is straight then the speed is constant. A slanted straight line on this type of grapgh means that the object is accelerating at a constant speed. Found by calculating slope of the line by choosing any two points. And then use the formula: rise/run. 
         • Distance versus time graph
           • Used when you represent the motion of an accelerating object. A curved line means that the object is accelerating.