Rather than researching, just think about the factors that might affect how much force you can apply. It will likely help to draw a free body diagram of a person pushing something. In particular, think about what factors might limit the amount of force that can be applied.
Once you find out what factors you need to consider, then do some research to find the values of those factors. And once you get an answer, it may help to take Delphi51's suggestion regarding the bathroom scale to check to ensure you're in the right ballpark.