Retraction uses the annular area
A fictional ideal liquid-powered cylinder has a fifty-millimetre bore and a twenty-millimetre rod. The supplied classroom model applies six bar gauge pressure to the driven chamber and neglects opposing pressure and friction. A student uses the full piston area for both extension and retraction, predicting the same force in both directions. Another identifies the area occupied by the rod on the retraction side before calculating. This written exercise designs no lifting circuit, prescribes no pressure setting and establishes no safe holding method. It asks the learner to choose the correct effective areas, convert units consistently and explain why real pressure differences, losses and load control remain important beyond the ideal calculation.
1. Which areas apply?
Read the worked answer
Extension uses π(0.025 m)²; retraction uses π[(0.025 m)²−(0.010 m)²].
2. What approximate ideal forces follow?
Read the worked answer
At 600000 Pa, extension is approximately 1178 N and retraction approximately 990 N. These ideal values do not authorize a real load or establish an engineered safety margin.