ðə mˈoʊmənt ʌv ɪnˈɜːʃə ɐbˌaʊt ɐn ˈæksɪs ɪz ɐ mˈɛʒɚmənt ʌv hˌaʊ dˈɪfɪkəlt ɪɾ ɪz tʊ ɐksˈɛlɚɹˌeɪt ðə bˈɑːdi ɐbˌaʊt ðæt ˈæksɪs.
The moment of inertia about an axis is a measurement of how difficult it is to accelerate the body about that axis.