# speed and velocity

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Category: Education

## Presentation Description

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By: flowersun (21 month(s) ago)

By: flowersun (21 month(s) ago)

very good!

## Presentation Transcript

Motion

### Linear Motion :

Linear Motion Motion is easy to recognize but can be hard to describe The following are used to describe motion: speed, velocity and acceleration Each of these is a rate. A rate is a quantity divided by time. Motion along a straight line is sometimes called linear motion.

### All Motion is relative :

All Motion is relative All motion is relative to a reference. This means that we describe motion of an object compared to some other object

### Speed or Velocity :

Speed or Velocity What’s the difference between speed and velocity? Speed is a measure of how fast something is moving. It is the rate at which a distance is covered http://www.physicslessons.com/speed.jpg Measured in m/s, km/h, miles/hr, cm/s, etc…

### Speed or Velocity :

Speed or Velocity We use the terms loosely today, but there is a distinction. Velocity is a speed AND direction. See the arrow? http://www.sdsc.edu/~sallen/Cars.html

### Velocity and Speed :

Velocity and Speed In physics we distinguish between speed and velocity: Speed refers to how quickly an object moves (a scalar quantity). Velocity is defined as speed in a given direction or rate of change of position (displacement over time). Velocity refers to both the speed and direction of motion of an object (a vector quantity). Negative velocity means the object is moving in the opposite direction Motion at constant velocity means that both the speed and direction of an object do not change. In a car, we can change the velocity three ways: gas pedal to speed up, brake to slow down or steering wheel to change direction

### Instantaneous Speed :

Instantaneous Speed Instantaneous speed is speed at any instant in time. A speedometer measures speed in ‘real time’ (the instantaneous speed).

### Average Speed :

Average Speed Average speed is the average of all instantaneous speeds; found simply by a total distance/total time ratio The average speed of a trip:

### Speed and Velocity :

Speed and Velocity Take as an example, a car driving in a circle. The car is always going the same speed, but it’s direction, or velocity, is constantly changing. From Conceptual Physics

### Slide 10:

D S T Speed Magic Triangle T = time S = speed D = distance ÷ ÷ x

### Distance-Time Graphs :

Distance-Time Graphs

### Distance-Time Graphs :

Distance-Time Graphs

### Distance-Time Graphs :

Distance-Time Graphs

### Distance-Time Graphs :

Distance-Time Graphs