# Homework Help: Average Speed

1. Sep 28, 2006

### spoonthrower

A golfer rides in a golf cart at a speed of 3.10 m/s for 21.0 s. She then gets out of the cart and starts walking at an average speed of 1.20 m/s. for how long (in sec) must she walk if her average speed for the entire trip, riding and walking, is 1.90 m/s?

I know average speed = d/t I'm just confused b/c the distance and the time for the walking part is not given. Please help. Thanks.

This HW problem is for my college physics 101 class and nobody has any ideas? c'mon

Last edited: Sep 28, 2006
2. Sep 29, 2006

### Staff: Mentor

You are given all but how long she walks, and that is what you are supposed to find. How do you calculate the average speed where there are two parts to it? Hint -- speed is distance / time as you indicate. What is the total distance she travelled while on the cart? What would be the total distance she walked, if you knew the time?

3. Sep 29, 2006

### Rozenwyn

Have you forgotten that you .... posted this .. already ? Or you just don't like bumping threads ?

4. Sep 29, 2006

### Staff: Mentor

Wow, and you even wrote out the equation for them in that thread. Weird, why re-post?