i read this book that said that longbows had a range of only 60yrds.

my little cousin has this bow with arrow, and he is 10,so its not very powerful. the pull is a joke it is so easy to pull back, well i wanted to see how far i could shoot it so i aimed up some and released, and the thing went at least 100yrds, over the field and into the treeline. so how much more powerful were the mongol bows or the longbow?
it would seem that they would have much more powerful.