Speed Kills Well sometimes Sometimes I feel the
- Slides: 8
Speed Kills! Well, sometimes!
Sometimes I feel the need, the need for speed!
What is “Speed? ” • Speed is the description of movement from one place to another. – It tells you how fast the object gets from that spot to the other. • It is a characteristic of ALL objects! – Even those that are standing still have a speed of “zero. ”
There are several ways to look at the concept of speed. • In the simplest way you take the distance traveled and divide it by the time that it took to get to another point. – Since speed is a ratio of distance over time, the units for speed are a ratio of distance units over time units. • For example your car’s speedometer shows you the distance, 60 miles, over the time that it will take you to get that far, 1 hour. – Therefore you are going 60 miles per hour! » The word “per” means for every or for each. » If you traveled at that rate for 3 hours how far would you have traveled! » 180 miles!
Speed can also be deceiving! • Sometimes the eyes can play tricks on you!
You can also generalize it by associating the speed with a term that isn’t as precise as you would think. – For example you could say that it took an eternity to get there, and anyone that has traveled with little kids knows that an eternity can be a rather long time! • ARE WE THERE YET? – Or on the other hand you could say that someone was as fast as “Greased Lightning. ”
What is the formula for finding speed? Speed = Distance/Time or v = d/t • When we represent speed in a formula, we use the letter “V. ” – If this seems confusing remember that “V” stands for Velocity. • For this chapter it isn’t important but there is a difference between speed and velocity, but more about that in a moment. • Speed will always be shown as a certain distance traveled in a given time. – Meters/sec, Miles/Hr, etc. • Just like “Density” we can put this formula into a “TRIANGLE” and derive three formulas that we’ll be using from it!
What is the difference between SPEED and VELOCITY? • Speed as we all know is a single measurement that tells how fast you are going. • Velocity is the speed PLUS the direction! – In this example, 55 miles/hr is the speed. – 55 miles per hour due south is the velocity!
