Describing Motion

http://www.youtube.com/watch?v=DRb5PSxJerM

Speed The distance an object travels in a certain

amount of time.

› Average speed – Total distance divided by total time

› Constant speed - Speed that does not change over time

On your paper, describe an example of an object at a constant speed.

What is the formula for calculating speed?

Speed equals distance divided by time.

S = dt

Let’s Practice Calculating Speed

One side of a track is about 100 meters long. If it takes a person 20 seconds to run its length, how fast was the person running?

In your notebook, calculate this problem. Make sure you show all work!

Check Your WorkOne side of a track is about 100 meters long. If it takes a person 20 seconds to run its length, how fast was the person running?

› Speed = Distance ÷ Time

› Speed = 100 m ÷ 20 s› Speed = 5m/s

Remember to label

the UNITS!!

Velocity An object’s speed and direction at a

given time› The wind is blowing 65 km/hr from the

North.

On your paper, describe an example of velocity.

Acceleration A change in the direction or velocity of an

object over time – which may be:› A change in speed

Starting Stopping Speeding up (positive acceleration) Slowing down (negative acceleration)

› A change in direction Acceleration is caused by unbalanced forces. On your paper, describe an example of an

object accelerating.

Our first super hero is Fire Hawk, he represents Speed.

Our second hero is Rocket Man, he represents Velocity.

For our final super hero we changed it up and made him a super villain, his name is Steam Roller. He represents Acceleration.

http://marvel.com/games/play/31/create_your_own_superhero http://www.heromac

hine.com/

http://cpbherofactory.com/