Bisi lives 5km from school. She walks 1km at 4km/h and travels the rest of the way by bus at 16km/h. What is the average speed for the whole distance?
time walking = 1/4 hrs
time on bus = 4/16 = 1/4 hr
avg speed = total distance/ total time
= 5/(1/4 + 1/4)
= 10 km/h
Time walking =1/4 hour
Time on bus =4/16=1/4hr
Avg speed =total distance /total time =5/(1/4+1/4)
=10km/h
To find the average speed for the whole distance, we need to calculate the total time taken for Bisi to travel from her house to school.
First, we calculate the time taken for Bisi to walk the 1km distance. We can use the formula:
Time = Distance / Speed
Distance = 1km
Speed = 4km/h
Time taken for walking = 1km / 4km/h = 1/4 hour = 15 minutes
Next, we calculate the time taken for Bisi to travel the remaining distance by bus. The remaining distance is 5km - 1km = 4km.
Distance = 4km
Speed = 16km/h
Time taken for bus travel = 4km / 16km/h = 1/4 hour = 15 minutes
Now, we calculate the total time taken for the whole distance by summing up the time taken for walking and the time taken for the bus ride:
Total time taken = Time taken for walking + Time taken for bus travel = 15 minutes + 15 minutes = 30 minutes
Finally, we convert the total time taken to hours, since the average speed is usually measured in km/h:
Total time taken in hours = 30 minutes / 60 (minutes/hour) = 0.5 hours
To find the average speed, we use the formula:
Average speed = Total distance / Total time
Total distance = 5km
Total time = 0.5 hours
Average speed = 5km / 0.5h = 10 km/h
Therefore, the average speed for the whole distance from Bisi's house to school is 10 km/h.