A mass is being held steady by a force of 7 N at 0 degrees and an opposing but equating force of 40.3 N at 100 degrees. Find the mass of the object. Ʃ Force = Mass * Acceleration. I found the vertical contribution of force from the force at 100 degrees to be 40.9 N but I attempted to calculated the mass from this by using this at a normal force that would oppose weight and so I divided by 9.8 and found 4.17 kgs and that was wrong. What do I do?