How fast would you say these ants are going?   Maybe .5 miles per hour is a good guess.

What does "miles per hour" mean?   Everyone knows it means that if they walked for 1 hour, they'd go half a mile.


.5 mi/Hr is a SPEED.  SPEED is a fraction.  Math people say it's a ratio of distance to time.

SPEED=DISTANCE÷TIME          I WRITE IT LIKE THIS: SPEED=DISTANCE / TIME

EQUATIONS AND SAMPLE PROBLEMS


To find a speed, you must know the distance covered, and the time it took to move.

EXAMPLE:  It takes 14Hours for me to drive 1000miles.  What's my speed?
ANSWER: S=D/T=1000miles/14Hours=71.4mi/Hr


What if we need to find the time and we already know speed and distance?
We use this equation: TIME=DISTANCE/SPEED

EXAMPLE: I went 30meters at 2meters/second.  How long did it take?
ANSWER: T=D/S=30meters/(2m/sec)=15seconds  (notice that the "meters" cancel out)


And lastly, what if we need to find distance if we know speed and time?
DISTANCE=SPEED*TIME

EXAMPLE: How far can an arrow go if it flies at 350feet/sec for 4seconds?
ANSWER: D=S*T=(350ft/sec)*4sec=1400ft