There's no way 50 minutes is enough. You need at least 2 hours. As a PP said, it can take 20-30 minutes to get off a plane, and keep in mind that planes often begin boarding 30 minutes prior to departure. A 50-minute connection is very risky even domestically, and that's assuming your flight's on time.
It's even risker with international travel. A major international airport like Amsterdam can be very, very big, and you'll be disoriented and jetlagged. You might have to change terminals, which can be complicated, confusing, and time-consuming. Plus some countries put international travelers through security again during their layover (I don't know if Amsterdam does this, but I know I have had to do it twice at London Heathrow on my way between the US and Denmark). Some countries also make you go through customs even if you are only laying over and not staying in the country.
And you're not in a good position if you miss your flight. Missing a connection is not fun at home in the US. It's even more difficult in a foreign country where you don't speak the language.
So allow at least 2 hours. 3 hours wouldn't be too much.