Speed and Velocity

Speed Speed is the ratio of the distance an object moves to the amount of time it takes the object to move

Speed cont. If you are traveling 60 miles and it takes you an hour to get from point A to point B… you would be traveling at 60 miles per hour

Average speed is computed for the entire duration of a trip

Average speed cont. When traveling, you often vary your speed Average speed can be calculated by dividing the total distance you traveled by the amount of time it takes you to travel

Average Speed cont. Imagine you are driving to Raleigh and it takes you 2 hours. The distance to Raleigh is 120 miles 120 miles / 2 hours = 60 miles/ 1 hour Your average speed was 60mph

Graphing Motion You can graph motion by plotting an object’s Distance vs. time

Graphing cont. The slope of a line on a distance-time graph is speed

Graphing cont. You calculate slope by dividing the change in distance by the change in time

Graphing cont. If an object has constant acceleration, it’s graph will look like this…

Graphing cont. If an object has varying speed, its graph will look like this:

Graphing cont. If speed varies, an object can either: Have constant speed Accelerate Decelerate

Between 20-40 mins – Constant speed Between 40-60 mins Acceleration Between 60-100 mins deceleration

Velocity You also need to know the direction that an object is moving in Velocity is a description of both speed and direction of motion

Velocity cont. Example: If you are traveling south at 60mph your velocity would be: 60 mph South