Sally travels by car from one city to another. She drives for 25.0 min at 71.0 km/h, 45.0 min at 45.0 km/h, and 43.0 min at 11.0 km/h, and she spends 10.0 min eating lunch and buying gas.
What is the average speed for the trip?what is the total distance traveled?
Average speed = (total distance)/(total time)
Total time = 25 + 45 + 43 + 10 minutes
Take it from there.
To find the average speed for the trip, we need to divide the total distance traveled by the total time taken.
First, let's calculate the distance traveled at each speed:
For the first leg of the journey, Sally drives for 25.0 min at a speed of 71.0 km/h. The distance travelled in this segment can be calculated using the formula:
Distance = Speed x Time
Distance = 71.0 km/h * (25.0 min / 60 min) = 29.58 km
For the second leg, Sally drives for 45.0 min at a speed of 45.0 km/h. Again, we can use the formula to find the distance:
Distance = 45.0 km/h * (45.0 min / 60 min) = 33.75 km
For the final leg, Sally drives for 43.0 min at a speed of 11.0 km/h:
Distance = 11.0 km/h * (43.0 min / 60 min) = 8.08 km
To find the total distance traveled, we simply sum up the distances from each leg:
Total distance = 29.58 km + 33.75 km + 8.08 km = 71.41 km
Now, let's find the total time taken:
Sally spends 10.0 min eating lunch and buying gas, so this time needs to be subtracted from the total travel time.
Total travel time = 25.0 min + 45.0 min + 43.0 min = 113.0 min
Final travel time = Total travel time - time spent eating lunch and buying gas
Final travel time = 113.0 min - 10.0 min = 103.0 min
Now, we can find the average speed:
Average speed = Total distance / Final travel time
Average speed = 71.41 km / (103.0 min / 60 min) = 41.69 km/h
Therefore, the average speed for the trip is 41.69 km/h and the total distance traveled is 71.41 km.