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MOTION. is a change in position of an object with respect to time any movement or change in position or place is always observed and measured relative to a frame of reference and its change in position to another reference frame. SPEED. Distance an object travels in a unit of time
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MOTION • is a change in position of an object with respect to time • any movement or change in position or place • is always observed and measured relative to a frame of reference and its change in position to another reference frame
SPEED Distance an object travels in a unit of time s = d / t speed = distance/ time Example: Bob drove to his parents house that was 60 kilometers away it took him 2 hours, How fast was he traveling? 60 kilometers / 2 hours = 30 km/hr or 30 kmh
How do we figure units? the UNIT for speed is Any distance unit over any time unit. Some distance units examples: m, cm, km, etc. Some time units examples are: hr, min, days, month, years, etc. ***when expressing units with division a forward slash means per ex. mi/ h (miles per hour) or m / s or ft / h
Solving for another variable -if s = d / t we can solve for any of these three variables -to solve for distance we would cross multiply both sides by the time, cancel, and then solve s = d / t t * s = (d / t) *t (the t’s cancel) to give you d = s * t - to solve for time you do the same with an extra step s = d / t t * s = (d / t) *t the t’s cancel to give you d = s * t then you divide by s on both sides d/ s = s * (t/ s) s’s cancel to give yout = d / s
3 Types of Speed 1- instantaneous- speed at any specific instance 2- average- total distance over a period of time interval, accounts for speed variations during time. ex. 32 km +13 km = 45 km = total distance 2 h + 1h = 3h = total time avg. speed = 45 km/ 3 h = 15 km/h 3- constant- when speed of an object does not vary. ex. satellite
1. A boat is traveling at a speed of 70 km per hour. It has to travel a distance of 210 km. How long will it take? 2. A car takes four hours to reach its destination. The distance was 340 km. What was its speed? 3. A car travels 300 km in six hours. What is the speed of the car? 4. What is the speed of a jet plane that flies 720 km in 9 hours? 5. The speed of a cruise ship is 50 km/hr. How far will it travel in 14 hours? 6. The speed of a rocket is 1200 km/hr, and it will take 6 hours to complete its mission. How far will it go? 7. What is the speed of a cyclist that travels 50 km in 2 hours? 8. A snail wants to participate in the Boston Marathon, a distance of 26 miles. His top speed is 0.01 km per hour. Assuming he maintains top speed for the entire race, how long will it take him to finish? 9. A rocket takes off at 800 km per hour and travels for 10 hours? What distance has the rocket traveled? Answer these Q’s then Compose 7 of your own and answer them p. 11 of your INB