A car travels up a hill at a constant speed of 40km/h and returns down the hill at a constant speed of 60km/h. Calculate the average speed for the round trip.
When I look at this I just think to add both 40 and 60 and divide by 2. Which gives me an average speed of 50 km/h.
Is this how to solve this problem with physics mentality?
Please explain.
Related posts:
2 responses so far ↓
1 rozeta53 // Jul 14, 2008
If s is the distance to the top of the hill, then the whole distance traveled is 2s.
The time needed to travel the distance of 2s is:
t=s/40 + s/60 ==>
The average speed:
v=2s/t=2s/(s/40 + s/60)
v=2*40*60/(40+60)
v=48 km/h
2 famila // Jul 14, 2008
Yeah u took it right.
Avg speed = (initial speed + final speed)/2
Ans = 50km/h
Leave a Comment