# Average speed

frizzler43
A person walks first at a constant speed of 5.01 m/x along a straight line from point A to B and then back along the line from B to A at a constant speed of 3.10 m/s

What is the average speed over the entire trip?

I've tried everything from adding the two and dividing by two. I've found that the avg. velocity over the trip is 0 m/s.
I know that avg speed=distance over time. I just don't know how you are suppose to find the time o if thats even what you're suppose to do

## Answers and Replies

Science Advisor
Homework Helper
welcome to pf!

hi frizzler43! welcome to pf!
… I know that avg speed=distance over time. I just don't know how you are suppose to find the time o if thats even what you're suppose to do

first, calculate the time for each half …

show us what you get

Mentor
I just don't know how you are suppose to find the time o if thats even what you're suppose to do
Find the time to go from A to B, then the time to go from B to A. Add to get the total. Hint: Express the time in terms of the distance, which you can just call D.

frizzler43
how are you suppose to find the time?

Science Advisor
Homework Helper
how are you suppose to find the time?

uhh?

speed = distance/time …

get on with it!