https://shkola.obozrevatel.com/ukr/books/7klass/fizika/2283/31--kolichestvo-teplotyi--edinitsyi-kolichestvo-teplotyi--udelnaya-teploemkost--raschet-kolichestva-teplotyi-neobhodimogo-dlya-nagrevaniya-tela-ili-vyidelyaemogo-im-pri-ohlazhdenii/82/