Hi and welcome to the Forum!
We are seeing more issues like this with regards to the ipad1 as it has only 256mb of ram compared to the ipad 2 with 512mb.
Ram is what enables all apps to run, some like gaming apps with lots of graphics and certain sites on Safari need more ram to run smoothly. There are steps you can do which will minimize this happening. Go to Settings - Safari and clear out your history and cookies regularly, limit location services you have and close apps completely when you are finished using them.
From the home screen do the four finger swipe up or double press the home button to reveal your multi task bar. These are all the apps that you have opened at one time. Long press the app until it jiggles and a red minus sign will appear above it. Press the minus sign, this will close the app, not delete it, now press the home button to return to your screen. It's also a good idea to close all these apps, as it helps the iPad run smoothly.
Doing a restart of your iPad is also a good step to take occasionally. Press and hold the power off button, the one at the top right. You will see a slide appear to power off, slide this and the screen will go dark and a Whirly will appear. When the Whirly disappears your iPad is now off. Press the power button again until the Apple logo appears, this will take a few seconds and your iPad will restart.
These steps are all like a bit of housekeeping for your iPad and you may even notice it running faster now. Let us know how you go.
