The answer is the man pushing the couch against the floor because he is using his force to move an object. If I understood the question correctly, and I think I did. Then the answer must be C
Try This Method(substitute your values) Centripetal force = Mass X Velocity^2/ Radius <span>F= mv^2/r </span> <span>so 80.5 X 40^2/200 </span> <span>=644N</span>
