[LibGDX] Problem with moving and framerate

Hello! I have some problem with my player movement (i use vector2 to calculate the position) and the framerate of the game.
i see that if I run the game in my phone at 60fps the play jump the right height, but if i play the game in a phone with 30fps the play jump a lot too height.
i don’t understand why it appened, con somebody explain to me how i can resolve or how it works?
thanks in advice and sorry for my dab english :stuck_out_tongue: