Is the word física the same in Brazilian and European Portuguese?

Yes

The word "física" is identical in meaning, spelling, and grammar in both Brazilian and Continental Portuguese. The only difference is in pronunciation.

In Brazilian Portuguese, the vowels are generally more open, and the rhythm of the word is more syllable-timed, making the "i" and the final "a" very clear. In Continental Portuguese, unstressed vowels tend to be more reduced or "closed" (vowel reduction), and the rhythm is more stress-timed, which can make the unstressed syllables sound much shorter or more muffled to a Brazilian ear.

Brazilian Portuguese Examples

1. Eu amo a aula de educação física. (I love physical education class.)
2. A física é uma matéria muito difícil. (Physics is a very difficult subject.)
3. Ele tem uma força física incrível. (He has incredible physical strength.)
4. A lei da física explica o fenômeno. (The law of physics explains the phenomenon.)
5. O curso de física é bem legal. (The physics course is really cool.)

Continental Portuguese Examples

1. Eu gosto imenso da aula de educação física. (I like physical education class very much.)
2. A física é uma disciplina bastante complexa. (Physics is a quite complex subject.)
3. Ele possui uma força física extraordinária. (He possesses extraordinary physical strength.)
4. A lei da física explica o fenómeno. (The law of physics explains the phenomenon.)
5. O curso de física é muito bom. (The physics course is very good.)