It can't be less than 250 N or the cart wouldn't move at all. That means there is only 1 answer. It's between not enough info or 250 N. The answer is 250 N. If it was any more, there would be acceleration.
Hello,
The answer is to "prove your hypothesis".
Reason:
Researchers do experiments to prove there hypothesis they will most likely do the experiment a few times in older to have the conclusion valid therefore proving his or her experiment.
If you need anymore help feel free to ask me!
Hope this helps!
~Nonportrit
