Sally travels by car from one city to another. She drives for 40.2 min at 80.0 km/h, 12.0 min at 105 km/h, and 45.0 min at 40.0 km/h. She spends 13.7 min eating lunch and buying gas.

Question

(a) Determine the total distance traveled in km.
(b) Determine the average speed for the trip in km/h.

Answer 1

use minutes/60 to get times in hours

.67 * 80 = 53.6
0.2 * 105 = 21
.75 * 40 = 30
.228 *0 = 0
--------------- add times and distances
1.85 hr 104.6 km
so
(a) 104.6 km
(b) = 104.6/1.85 = 56.5 km/hr

Answer 2

Sally travels by car from one city to another. She drives for 20.0 min at 64.0 km/h, 37.0 min at 43.0 km/h, and 18.0 min at 66.0 km/h, and she spends 10.0 min eating lunch and buying gas.

(a) Determine the average speed for the trip.
1 . km/h
(b) Determine the total distance traveled.
2 . km

Answer 3

a)91.0 km
b)53.5 km/h