med-physics: command not found

Maybe Your $PATH variable doesn't contain the default paths? echo $PATH should give something like:

[root@server ~]# echo $PATH
/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin

If it's empty, You may set the PATH variable with this command

export PATH="/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin"

On Debian possible default full paths are:

/usr/bin/med-physics - from package: med-physics

You may install the required package with command apt-get install {package}

Error in other languages:
med-physics: bevel nie gevind nie
med-physics: comandă negăsită
med-physics: comando não encontrado
med-physics: commande introuvable
med-physics: command not found
med-physics: käsku ei ole
med-physics: không tìm thấy lệnh
med-physics: komanda nerasta
med-physics: Kommando nicht gefunden.
med-physics: kommandot finns inte
med-physics: komut yok
med-physics: nie znaleziono polecenia
med-physics: níor aimsíodh an t-ordú
med-physics: no se encontró la orden
med-physics: no s'ha trobat l'ordre
med-physics: opdracht niet gevonden
med-physics: parancs nem található
med-physics: perintah tidak ditemukan
med-physics: príkaz nenájdený
med-physics: příkaz nenalezen
med-physics: команда не найдена
med-physics: командата не е открита
med-physics: 命令找不到
med-physics: コマンドが見つかりません