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

Yes

The word "usamos" is identical in meaning, grammar, and spelling in both Brazilian and Continental Portuguese. The only difference is pronunciation. In Brazilian Portuguese, the vowels are generally more open and clearly articulated. In Continental Portuguese, unstressed vowels (such as the "a" in the penultimate syllable) are often "reduced" or swallowed, making the word sound more compressed or "clipped" to a Brazilian ear.

Brazilian Portuguese

1. Nós usamos o celular para trabalhar. (We use the cell phone to work.)
2. Usamos o ônibus para ir à escola. (We use the bus to go to school.)
3. Nós usamos muito açúcar no café. (We use a lot of sugar in the coffee.)
4. Usamos roupas de frio no inverno. (We use cold-weather clothes in winter.)
5. Nós usamos aplicativos para estudar. (We use apps to study.)

Continental Portuguese

1. Nós usamos o telemóvel para trabalhar. (We use the mobile phone to work.)
2. Usamos o autocarro para ir para a escola. (We use the bus to go to school.)
3. Nós usamos muito açúcar no café. (We use much sugar in the coffee.)
4. Usamos roupa de frio no inverno. (We use cold-weather clothing in winter.)
5. Nós usamos aplicações para estudar. (We use applications to study.)