a tortoise walks north at 0.4 mg for 14 meters, then north at 0.2mg for 30 meters ,then south at 0.3 m/s for 60 meters.what is his average speed?
Assuming you mean m/s not mg.
North at 0.4 m/s for 14 m takes 35 s.
North at 0.2 m/s for 30 m takes 150 s.
South at 0.3 m/s for 60 m takes 200 s.
Speed is independent on direction.
Average speed is:
= (total distance)/(total time)
To find the average speed, we need to calculate the total distance covered by the tortoise and divide it by the total time taken.
First, let's calculate the total distance covered by the tortoise:
Distance covered in the first leg (north at 0.4 m/s for 14 meters) = 0.4 m/s * 14 m = 5.6 meters
Distance covered in the second leg (north at 0.2 m/s for 30 meters) = 0.2 m/s * 30 m = 6 meters
Distance covered in the third leg (south at 0.3 m/s for 60 meters) = 0.3 m/s * 60 m = 18 meters
Now, let's calculate the total time taken by the tortoise:
Time taken in the first leg = 14 meters / 0.4 m/s = 35 seconds
Time taken in the second leg = 30 meters / 0.2 m/s = 150 seconds
Time taken in the third leg = 60 meters / 0.3 m/s = 200 seconds
The total distance covered by the tortoise is 5.6 + 6 + 18 = 29.6 meters, and the total time taken is 35 + 150 + 200 = 385 seconds.
Finally, we can calculate the average speed:
Average speed = Total distance / Total time = 29.6 meters / 385 seconds ≈ 0.0766 m/s
Therefore, the average speed of the tortoise is approximately 0.0766 meters per second.