(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

Julie drives 100mi to Grandmother's house. On the way to Granmothers, Julie drives half thedistanceat 40mph and half the distance at 60mph. On the returntrip, she drives half thetimeat 40mph and half at 60mph.

What is her average speed on the return trip?

2. Relevant equations

v = v[0] + a dt

s[f] = s[0] + v[0] dt + 1/2 a dt^2

3. The attempt at a solution

I need to find the time first I think and then do .5*40t + .5*60t but I'm not sure how to find t

**Physics Forums | Science Articles, Homework Help, Discussion**

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Homework Help: Motion Problem, Find Average Speed

**Physics Forums | Science Articles, Homework Help, Discussion**