Speed vs. Velocity

Now we know how to make a graph, and maybe how to read it.

What's Next? Speed and Velocity - Are they the same thing?

If not, can you come up with a good example of how they are different?

In class, we associated linear motion with speed - is velocity related to linear motion?

Linear Motion: Average, Constant & Instantaneous Speed

Questions from Class - Based on your understanding of Speed:

What does speed measure?

What is the Formula for Average Speed?

What is the difference between average speed and instantaneous speed?

An airplane is flying at a constant (also called “uniform”) speed of 400 miles an hour for three hours.
1. What is the plane’s instantaneous speed two hours into the flight?
2. How far will the plane travel in three hours?
3. How far will the plane travel in thirty minutes?

A runner runs at a constant speed of 7 mph in a marathon (note: a marathon is a race of 26.2 miles).
1. How far would she run in:
- One hour?
- Two hours?
- Three hours?
- Three hours, 30 minutes?
2. What was her time at the 14 mile mark?
3. What was her average speed during the race?

Extra Credit: One point each, answers must be precise to the second. Print this out and give it to Mr. Barkan with your answers (show ALL work or no credit!) no later than 2:30 pm on Thursday, November 1st for credit.
i. How long (in hours, minutes and seconds) did it take her to finish the marathon?
ii. What was her pace per mile? (i.e., How long, in minutes and seconds, did it take her to run a mile at that pace)?
iii. If she ran the marathon at a constant speed of 10 minutes per mile, how long would it take her to finish?
iv. What are the current NYC Marathon Men’s and Women’s Course Records?
v. What pace (constant speed) would a Male and a Female runner have to maintain to beat the current NYC Marathon Course Records?
vi. What will the winning times be for the first male and female finishers at the NYC Marathon on Sunday, November 4th, 2007?

Linear Motion

The rules governing how things move along a line are known (formally) as One Dimensional Kinematics and are part of the branch of physics commonly referred to as Newtonian mechanics.

Our first formal investigation into the world of Newtonian mechanics saw a bowling ball being hurled down 120 feet of hallway.

Our investigation of this linear motion (motion in a line) began with timing how long it took the ball to pass by eight marked points, each 15 feet long.

We will use this investigation to determine how to measure and predict the "simple" motion of an object moving in a straight line.

Our first task will be to determine the speed of the ball.
Those students who have taken the time to read this will know that while we can try to figure out the ball's speed every 15 feet mathematically, it will prove far simpler to graph the data and interpret the graph to answer the question of what happened to the ball's speed as it moved down the hallway.