You drive a car 2.0 km to the gas station, 4.0 km to the shopping mall to let your mother off, and 4.5 km back home. The trip takes 20.0 min. What is your average speed?
r = d/t = (2+4+4.5)/(20/60)h = 31.5km/h.
Henry almost had it right....
s=(2+4+4.5)km/ 20min --> convert to m/s: s=10.5km/20min x 1000m/1km x 1min/60s --> 8.75 m/s
To calculate average speed, you need to divide the total distance traveled by the time taken. In this case, the total distance traveled is the sum of the distances to the gas station, shopping mall, and back home: 2.0 km + 4.0 km + 4.5 km = 10.5 km.
The time taken for the trip is given as 20.0 minutes.
To calculate average speed, divide the total distance (10.5 km) by the time taken (20.0 min) and convert the time to hours:
20.0 min / 60.0 min/hour = 0.3333 hours.
Now, divide the total distance (10.5 km) by the converted time (0.3333 hours) to find the average speed:
10.5 km / 0.3333 hours ≈ 31.51 km/h.
Therefore, your average speed for the trip is approximately 31.51 km/h.