In the Tough Man Competition, very strong men are challenged to push or pull extremely large and heavy objects to test their strength. In one such challenge, they were asked to push one of two rail cars, an engine car and a box car. The data tables show one man's results.

Did it move the engine car?:
1000 newtons: no
2000newtons: no
3000 newtons: yes

Did it move the boxcar?:
1000 newtons: no
2000 newtons: no
3000 newtons: no

A: Why couldn’t the strong man move the box with a force of 3000 Newtons?

B: What could be done to move the boxcar

C: Another Student claims that during the competition, the sum of the forced on the boxcar was 0 N. What evidence is the student using to make this claim? Be sure to explain

Ashielded metal arc-welding operation is accomplished in a work cell by a fitter and a welder. the fitter takes 5.5 min to load components into the welding fixture at the beginning of the work cycle, and 1.5 min to unload the completed weldment at the end of the cycle. the total ength of the weld seams 1200 mm, and the travel speed used by the welder averages 300 mm/min. every 600 mm of seam length, the welding stick must be changed, which takes 0.8 min. while the fitter is working, the welder is idle (resting): and while the welder is working the fitter is idle. (a) determine the average arc-on time as a fraction of the work cycle time. (b) how much improvement in arc-on time would result if the welder used flux-cored arc welding (manually operated), given that the spool of weld wire must be changed every 10 weldments, and it takes the welder 5.0 min to accomplish the change? (c) what are the production rates for these two cases (weldments completed per hour)? attach your work and solutions.