Average speed when covering 99 km at different velocities

[mpoole]

1. A car making a 99-km journey travels 38 km/h for the first 49.5 km. How fast must it go during the second 49.5 km to average 47 km/h?



2. Homework Equations ?



3. 47=.5(38+x)

 

[SteamKing]

You need to consider time in your solution. For example, if the average speed is 47 km/h and the distance traveled is 99 km, how long should this take to occur?

 

[Simon Bridge]

Welcome to PF;
You didn't provide a lot of information - i.e. the "relevant equations" section is not filled in.
It is difficult to know what sort of reply will best fit your need.
From the unfinished calculation in section 3, we can make a guess but we could guess wrong.

Did you have a specific question for us or did SteamKing manage to cover it?