Humans can perceive causality when viewing collision-like interactions between plain, two-dimensional shapes. To what extent subjective causality reports arise from the physical plausibility of events as predicted by Newtonian physics remains an open question. Here we measured each participant’s perceptual judgments about the contact point angle ($\alpha$) and their causality judgments about the target ball's trajectory offset ($\beta$) using Michotte’s launching paradigm. Our results showed that subjective causality reports decreased as the target’s trajectory deviated further from the physically plausible angle, confirming the important role of physical plausibility in causal perception. Moreover, as uncertainty about $\alpha$ increased, participants were more likely to report events with larger $\beta$ as causal, and their causality reports were more sensitive to changes of $\beta$, consistent with a mental physics model that incorporates $\alpha$. These findings align with predictions of causality perception under a Noisy Newton framework, and provide experimental evidence using individualized uncertainty estimates.