関連ワード:  define 1 j of work for class 9    define 1 joule of work for class 9    define 1 joule of work for class 9 physics    define 1 j of work class 9 short answer    define 1 j of work class 9th ncert    define 1 j of work class 9 science    define 1 j of work class 9th answer    define 1 joule of work class 9 short answer    define 1 joule of work class 9 science    define 1 joule of work class 9 very short answer