6th Grade Motion, Forces & Energy (Mod I) Unit 1 Lesson 1 Motion and Speed 6th Grade Motion, Forces & Energy (Mod I) Unit 1 Lesson 1

Describing location Position IS the location of an object We often describe a position by comparing it to the location of something else This “something else” is called a reference point Reference point = location you compare other locations to

position and relative motion with toy cars Do 5, 6 & 7 p. 6 & 7

Motion is a change in position over time An object changes its position relative to a reference point What if the skater started and stopped in the same place? Did he move? Yes…So it looks like we need MORE ways to think about motion A change in position is PROOF that motion has happened!

Distance = how far you go The distance between 2 points is different, depending on how you get there Scientists use meters (m) and kilometers (km) to measure distance Do #8 on p. 8 The Difference between Distance and Displacement

Speed = how far something moves in a certain amount of time A.k.a. - How quickly or slowly the object changes position In the same amount of time, a faster object would move a greater distance than a slower one. Speed is not always constant Average speed describes the speed over a stretch of time.

How far (distance) did the tortoise go? 130 ft. How far did the hare go? 200 ft. How much time did it take the tortoise to go 130 ft? 10 minutes How much time did it take the hare to go 200 ft? 6 minutes

TELLING STORIES WITH GRAPHS What story does this graph tell? Steeper lines = faster speed Horizontal line = object has stopped

To calculate average speed Divide the distance an object travels by the time it takes to cover the distance. Speed = s Distance = d Time = t

Fun with formulas!

A penguin swimming underwater goes 20 meters in 8 seconds A penguin swimming underwater goes 20 meters in 8 seconds. What is its average speed? (page 10) Identify: A. What do you know? B. What do you want to find out? Plan: C. Draw and label a sketch D. Write the formula E. Substitute into the formula Solve: F. Calculate and simplify G. Check that your units agree Answer: Now YOU try! Page 11

Graphing constant speed Distance-time graph X-axis = time Y-axis = distance Graph my road trip! 1cm = 20km

Which car is faster?

Graphing changing speed What is the difference between the speed at a particular time and average speed? Steeper lines = faster speed Horizontal line = object has stopped

Quick quiz! Q: What do we need to describe an object’s location? A: the object’s position and a reference point. Q: What do we need to find an object’s speed? A: The distance it traveled and how much time it took to get there. Q: If I ran 50 meters in 25 seconds, what is my speed? A: 2 m/s

Velocity Read and do pg. 15 Speed in a specific direction Speed vs. velocity song Velocity is an example of a vector quantity – we measure both how BIG it is and the DIRECTION it goes we studied FORCE this year – it is also a vector quantity, because we talked about how MUCH force and the DIRECTION of force Scalar quantities only show how MUCH of that thing there is. Speed, temperature, distance are all scalar – try this quiz! vector vs. scalar quiz Two things can have the same speed but different velocities (how?) Average SPEED is calculated by dividing the total distance by the total time. Average VELOCITY is calculated by dividing the displacement (straight-line distance) by the time. Read and do pg. 15