GPS battery usage as a function of how often it is pinged for data Consider an app that uses GPS to get location details.  Those types of apps often use a lot of battery power.  Here is what I am wondering; let say one app get the details every 5 seconds, and another gets that info every 10 seconds.  Would the second app use half the battery power or would it be about the same since the GPS is ready to be used whether it is asked more or less often?  Thank you.
It won't make a noticeable difference. The GPS receiver has to be powered up continuously either way, but the receiver itself isn't a huge part of the battery use of most location-based apps. In general, this kind of app can be a battery drain because it's running, computing data, and saving data continuously. For example, if it's saving a log of your route, it has to get the GPS locations, filter and process those locations, and save them to the storage, continuously. All the time it's doing this, the phone's CPU is still running at high power, when normally it would be asleep (in a low-power state) in your bag or pocket.

The difference between how much other work the two apps are doing, and how efficient they are at that, is going to dwarf any difference caused by location sampling rates. In fact the difference between the apps themselves might even be more than the total power consumption of the GPS receiver.