viewimage.php?id=3db5c935ecd12bf4&no=24b0d769e1d32ca73deb87fa11d02831de04ca5aee4f7f339edb1d2bd94f7835955f01cd62ba42c4ba6b7a21d24475fb1ca8b453e405bc7215daa105cb21157f695f01

잘 풀면 예쁜 숫자

두 물체의 질량은 동일함