i have a test on friday and i know these kinds of questions will be on it, but i just cant figure it out. here's a real easy version of those questions and i was hoping you guys could clear up for me the basic way to do this: a man finds that a 6N force will pull a toy wagon along a level table at a constant velocity. He also finds that a 42N force will accelerate the same wagon at 3.0m/s2 along the same table. what is the mass of the wagon? thanks for your help!