the teacher: 15 seconds after the buzzer, the teacher has 135 meters to go to the finish line. 32 seconds after he left the starting line, the teacher has to run 50 meters more to the finish line. Usain Bolt: 22 seconds after the buzzer, usain has 189 meters to finish. 36 seconds after the buzzer, he has 42 meters to the finish line.
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why are you reposting this?
Steve already did it for you
http://www.jiskha.com/display.cgi?id=1476313817
To find out how fast each of them are running, we can calculate their average speed using the distance they have left to run and the time it takes for them to reach the finish line.
For the teacher, we will use the information provided:
- 15 seconds after the buzzer, the teacher has 135 meters left to go.
- 32 seconds after leaving the starting line, the teacher has 50 meters more to run.
To find the teacher's average speed, we can calculate the difference in distance over the difference in time. First, we calculate the time it took for the teacher to cover the extra 50 meters:
32 seconds - 15 seconds = 17 seconds
Next, we calculate the average speed by dividing the difference in distance by the difference in time:
Average Speed = (135 meters - 50 meters) / 17 seconds
Simplifying, we have:
Average Speed = 85 meters / 17 seconds
Average Speed = 5 meters/second
Therefore, the teacher's average speed is 5 meters/second.
Now let's calculate Usain Bolt's average speed.
- 22 seconds after the buzzer, Usain has 189 meters left to go.
- 36 seconds after the buzzer, he has 42 meters left to the finish line.
Using the same method as before, we can calculate the difference in distance and time:
Difference in time: 36 seconds - 22 seconds = 14 seconds
Difference in distance: 189 meters - 42 meters = 147 meters
Next, we calculate the average speed by dividing the difference in distance by the difference in time:
Average Speed = 147 meters / 14 seconds
Average Speed = 10.5 meters/second
Therefore, Usain Bolt's average speed is 10.5 meters/second.