Newly bought ipad5 is lagging

This maybe normal.

To keep the costs low on the 2017 iPad 5, Apple has used an iPhone 6 type CPU chip instead of an iPad centric CPU chip.

So, it is not “quite” as powerful enough to drive the graphics of a larger screen iPad.

This has been reported here by a number of other 2017 iPad 5 users, as well.

So, there maybe no fix for this cost-cutting measure.

I am guessing "iPad 5" means the fifth generation of iPad, which Apple calls "iPad Air".

The iPad Air was released in late 2013, and discontinued in March, 2016. So I am guessing you bought it as a previously owned device.

All this aside, it is hard to know what "lagging" means exactly. It might mean, for example:

• When I type keystrokes, the iPad responds slowly (e.g., echoing the keystrokes on the screen).
• When I attempt to access the internet, sites load slowly in Safari.
• Videos play slowly.
• When reading an iBook, pages turn slowly.

Clearly we need much more information.

The new 2017, 9.7 inch iPad is called by Apple, the iPad 5th generation or iPad 5.

It is the 5th version of a plain ’ole iPad. No Air, Mini or Pro adjectives.

Agreed.

However, the fifth generation iPad was actually the iPad Air, and as you can see here, references to iPad (fifth generation) were formerly referring to the iPad AIr.