2025 · Paper 2 · Physics
Question 15
The printed question, the official key, and each model’s JSON answer plus the reasoning it wrote.
PhysicsPaper 2Numerical
Q15
Official 167 – 171
Model answers
Claude Fable 5.1
Anthropic
Correct4 / 4
170
Claude Fable 5.1 reasoning
Horizontal motion with linear drag: m dv_x/dt = −c v_x, so v_x = v₀cos60° · e^(−ct/m). x(t) = (m v₀ cos60°/c)(1 − e^(−ct/m)) Values: m = 0.2 kg, c = 0.1 kg/s, so m/c = 2 s and ct/m = 1 at t = 2 s. v₀cos60° = 270 × 0.5 = 135 m/s x = 135 × 2 × (1 − 1/2.7) = 270 × (1.7/2.7) = 170 m
GPT 6 Astra
OpenAI
Correct4 / 4
170
GPT 6 Astra reasoning
No written reasoning was returned for this item.
GPT 5.6 Luna
OpenAI
Correct4 / 4
170
GPT 5.6 Luna reasoning
No written reasoning was returned for this item.