Probleme scanf : saut de ligne

#include <stdio.h>
#include <conio.h>

main()
{
      float note1,note2,note3,coefficient,note_finale,note_finale1,note_finale2,note_finale3,moyenne_generale;
      printf("Matiere");
      printf("\t    Note/20");
      printf("\tCoefficient");
      printf("\tNote finale");
      printf("\n\nMath\t    ");
      scanf("%f",&note1);
      printf("\t\t\t");
      printf("2\t\t");
      note_finale1=note1*2;
      printf("%.2f",note_finale1);
      printf("\n\nphysique    ");
      scanf("%f",&note2);
      printf("\t");
      printf("\t\t1\t\t");
      note_finale2=note2;
      printf("%.2f",note_finale2);
      printf("\n\njava\t    ");
      scanf("%f",&note3);
      printf("\t\t\t");
      printf("3\t\t");
      note_finale3=note3*3;
      printf("%.2f",note_finale3);
      note_finale=note_finale1+note_finale2+note_finale3;
      coefficient=6;
      moyenne_generale=note_finale/coefficient;
      printf("\n\nla moyenne generale est : %.2f/20 ",moyenne_generale);
      
   
      getch();
}