Sally travels by car from one city to another. She drives for 28.0 min at 63.0 km/h, 50.0 min at 40.0 km/h, and 50.0 min at 43.0 km/h, and she spends 13.0 min eating lunch and buying gas.
Find the trip's average speed and total distance traveled...
To find the trip's average speed, we need to first calculate the total distance traveled.
Distance = Speed * Time
For the first segment of the trip, Sally drives for 28.0 min (0.47 hours) at a constant speed of 63.0 km/h.
Distance1 = 63.0 km/h * 0.47 h = 29.61 km
For the second segment, she drives for 50.0 min (0.83 hours) at a speed of 40.0 km/h.
Distance2 = 40.0 km/h * 0.83 h = 33.2 km
For the third segment, she drives for 50.0 min (0.83 hours) at a speed of 43.0 km/h.
Distance3 = 43.0 km/h * 0.83 h = 35.69 km
Now we can calculate the total distance traveled by adding all the distances:
Total Distance = Distance1 + Distance2 + Distance3 = 29.61 km + 33.2 km + 35.69 km = 98.5 km
Next, we need to calculate the total time taken for the trip. Sally spends 13.0 min (0.22 hours) eating lunch and buying gas. Adding up all the driving times:
Total Time = 28.0 min + 50.0 min + 50.0 min + 13.0 min = 141.0 min = 2.35 hours
Now we can find the trip's average speed:
Average Speed = Total Distance / Total Time = 98.5 km / 2.35 hours ≈ 41.91 km/h
So, the trip's average speed is approximately 41.91 km/h, and the total distance traveled is approximately 98.5 km.
avg speed = total distance/time
total distance= rate1*time1 + rate2*time2 + ....
change minutes to hours.