Motion An object changes position, over time, compared to (a) reference point(s). If this sounds picky… it can be hard to tell if you’re moving. On an airliner, you’re going 500+ mph but it feels like you’re standing still. Until turbulence changes the plane’s velocity

Motion is Relative! A girl standing still tosses a ball in the air, it looks like the ball goes up and down. If you’re both in a car going 55 mph, to you it looks like the ball is going up and down while the world is rushing by. To a kid waiting at a crosswalk in Linton the ball is going forward as fast as the car and up and down as well.

Are the stars moving or are we? Ancient people thought the stars were moving and the Earth stood still. Thanks to Copernicus and Galileo we now know that the Earth is moving and so are the stars. We are standing on a planet spinning on it’s axis, orbiting the sun that is a part of a spinning galaxy expanding outward every moment...but it feels like we’re standing still.

How do We Measure Motion? Speed = rate of change in position Speed = distance ÷ time s = d/t When you’re in a car speed is measured in miles (distance) per hour (time) or mph.

Example: A car went 110 miles in 2 hours, what is its speed in mph? First write out the formula s=d÷t Plug in the numbers (include units) s= 110miles ÷ 2 hours Do the math; s= 55 mph Your answer must include units.

Example 2: Rare Bear 528.33 mph Fastest piston engine propeller plane ever. Portland to Clatskanie (~78.0 miles) in 8.9 minutes! What’s it’s speed in miles per minute? S= d ÷ t S = 78.0 miles ÷ 8.9 minutes S = 8.8 miles per minute (Clatskanie to Rainier in 82 seconds!)

Speed Machines You will need this handout.

1. One of the fastest Nascar racers on the circuit recently traveled 600 miles in 4 hours? What is the car’s average speed? Speed = distance ÷ time Speed = 600 miles ÷ 4 hours Speed = 150 mph

2. The German-made Thrust SSC is the fastest car on Earth 2. The German-made Thrust SSC is the fastest car on Earth. It covered a one mile course in 0.0013 hours. What was its speed in miles per hour? Speed = distance ÷ time Speed = 1mile ÷ 0.0013 hours Speed = 769 miles/h Click on the image to play

3. The fastest train on Earth, the TGV from France, traveled 800 miles in 2.5 hours. What was its average speed? Speed = distance ÷ time Speed = 800 miles ÷ 2.5 hours Speed = 320 mph Video

4. The Spirit of Australia a hydroplane, broke boating speed records by traveling 239 miles in 0.75 hours (45 minutes). What was its record breaking speed? Speed = distance ÷ time Speed = 239 miles ÷ 0.75 hours Speed = 319 mph

Speed = distance ÷ time Speed = 2,300miles ÷ 1.06 hours 5. The fastest plane ever, the SR-71 Blackbird, in a record breaking flight went from Los Angeles to Washington D.C. (a distance of ~2,300 miles) in about 1.06 hours. What was its speed on this record setting trip? Speed = distance ÷ time Speed = 2,300miles ÷ 1.06 hours Speed = 2,167 mph video

Speed = distance ÷ time Speed = 960 miles ÷ 0.2 hours 6. The X-15 was faster, but did not take off under it’s own power, it was dropped from a B-52 mother plane. After clearing the mother and igniting it’s engines, the X-15 could travel 960 miles in 0.2 hours. What was it’s speed in miles per hour (mph)? Speed = distance ÷ time Speed = 960 miles ÷ 0.2 hours Speed = 4,800 mph Movie

7. The fastest air breathing unmanned craft, the X43A scramjet, it reached Mach 6.8 (Mach 1 = speed of sound). At this speed it could travel 7752 miles in 1.5 hours. What is it’s speed in miles per hour? Speed = distance ÷ time Speed = 7752 miles ÷ 1.5 hours Speed = 5,168 mph video

? Fastest Humans Ever! Apollo launch The highest speed ever achieved by a manned vehicle is 39,895 km/hr (24,790 mi/hr). What was the vehicle and who were the three voyagers inside? Answer: Apollo 10 (1969) during reentry.                                          (C) Thomas P. Stafford Commander (R) John W. Young Command Module Pilot (L) Eugene A. Cernan Lunar Module Pilot

Velocity is Not the Same as Speed. Velocity is speed plus direction. Velocity can change if an object speeds up, slows down, or changes direction

Acceleration The rate of change in velocity Positive acceleration = speeding up Negative acceleration = slowing down (decelerate) Acceleration = Vfinal – Vinitial Time or = ∆Velocity

Acceleration Causes a Force You Can Feel. When a car speeds up rapidly, you are pushed backward. If the car stops abruptly, you lurch forward. If the car goes fast around a sharp corner, you are pushed toward the outside of the corner.

Example: A car goes from 10 mph to 50 mph in 4 seconds, what is its acceleration Write down the formula; a= change in speed ÷ time Plug in the numbers; a = (50 mph – 10 mph)÷ 4 sec Do the math a = 40mph ÷ 4 sec = 10mph/sec

You will need this handout

1. What is acceleration? How can you tell if you are accelerating? You feel a force You’re speed might be the same, but you’re velocity is changing You’re speeding up, slowing down, or changing direction.

2. A Lamboghini Murcielago LP640 went from 0 to 60mph in 3 2. A Lamboghini Murcielago LP640 went from 0 to 60mph in 3.3 seconds what is it’s acceleration in m/h/s? a = Vfinal – Vinitial ÷ time a = (60mph – 0mph) ÷ 3.3 sec. a = 18.8 miles/h/s

3. The Ford RS200 Evolution did 0 to 45mph in 2 3. The Ford RS200 Evolution did 0 to 45mph in 2.1 seconds what is it’s acceleration in miles/h/s? a = Vfinal – Vinitial ÷ time A = (45 mph – 0mph) ÷ 2.1 sec. a = 21.4 miles/h/s

4. The Bugatti Veyron did 30 to 60 mph in 1. 25 seconds 4. The Bugatti Veyron did 30 to 60 mph in 1.25 seconds. What is it’s acceleration in miles/h/s? a = Vfinal – Vinitial ÷ time a = (60mph – 30mph) ÷ 1.25 sec. a = 24 miles/h/s

5. Mr. Kay’s SUV goes from 60mph to 0mph in 6. 2 seconds 5. Mr. Kay’s SUV goes from 60mph to 0mph in 6.2 seconds. What is it’s acceleration? (be careful, is he going faster or slower?) a = Vfinal – Vinitial ÷ time a = (0mph – 60mph) ÷ 6.2 sec. a = -9.8 miles/h/s He is slowing down to a stop.

What is each car doing? The blue car (squares) is standing still The red car (diamonds) is going at a slow constant speed The green car (triangles) is accelerating D i s t a n c e Time