Two masses, m₁ = 3.0 kg and m₂ = 5.0 kg, are connected by a light string over a frictionless pulley (Atwood machine). What is the acceleration of the system? Use g = 9.8 m/s².
A1.2 m/s²
B2.45 m/s²
C4.9 m/s²
D9.8 m/s²
Explanation
📌 Atwood formula: a = (m₂ − m₁)·g / (m₁ + m₂) = (5.0 − 3.0)(9.8) / (5.0 + 3.0) = 19.6/8.0 = 2.45 m/s². Distractor A used mass ratio incorrectly; C used (m₂ − m₁)/2 without dividing by total mass; D used g alone (ignored mass balance).