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Section 1.2 Speed measures how fast position changes. MRS. LEOS How far is Wet ‘n Wild? What are different ways to describe how far somewhere is? EXPLORE: (page 16) How can you measure speed? PURPOSE: To introduce the relationship among speed, distance, and time. How can you measure speed? Read through procedure on pg 16 Answer What do you think Questions in ISN. Position can change at different rates. Speed is a measure of how fast something moves or the distance it moves, in a given amount of time. The greater the speed an object has, the faster it changed position. Look at the picture on p 17 What does each group of numbers in a box represent? How can you tell which cyclist is pedaling faster? How far will each rider travel in 5 seconds? Calculating Speed Distance and time measurements The formula for speed (average) Speed = Distance/Time S = d/t Let’s practice! A wheelchair racer completes a 100-meter course in 20 seconds. What is his speed? A dog runs 200 m in 25 s on the beach. What is his speed? Raise your hand when you know the answer If a remote-control car travels 100 m in 50 s, what is its speed? Check your reading If two runners cover the same distance in different amounts of time, how do their speeds compare? Average Speed Instantaneous speed (moment-to moment speed) is hard to measure, therefore it is easier to calculate your average speed Distance-Time Graphs Shows how speed relates to distance and time TIME is on the x- axis (horizontal) DISTANCE is on the y-axis (vertical) IN YOUR OWN WORDS SUMMARIZE bullets 1,2,3 Calculating Speed from a Graph How fast is the zebra walking during the first 20 seconds? Practice Math problems Reading Visuals-Page 21 How do the distances change over each 10 second time interval? Velocity includes speed and direction Velocity= speed in a specific direction Example: walking east at a speed of three meters per second Vector: a quantity that has both size AND direction (velocity) Two objects can have the same speed but different velocities (same speed, different directions) On page 26 (left side of notebook), demonstrate your understanding of Section 1.2 Write your summary ( 5-7 sentences)