Which risk contributed to the eventual decline in effectiveness of Roman ballista siege engines during prolonged campaigns?

💡 Explanation

During prolonged campaigns, repeated stress on the ballista's sinew torsion springs caused creep, leading to reduced elasticity and diminished launch power because of material fatigue. Therefore weakened springs resulted, rather than increased bolt weight, frame cracking, or bronze corrosion which represent relatively slower acting degradation processes.

• Which mechanism enabled 11th-century scholars, such as Ibn al-Haytham, to improve lens grinding for optics?
• Which purpose did the alignment of ancient Egyptian temples like Karnak serve relative winter solstice sunrise?
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• Which mechanism causes the apparent retrograde motion of planets when observed using a medieval Islamic astrolabe?