Private Function Intersect(pic1 As PictureBox, pic2 As PictureBox) As Boolean
   If (pic1.Left < pic2.Left + pic2.Width) And (pic1.Left + pic1.Width > pic2.Left) Then
     If (pic1.Top < pic2.Top + pic2.Height) And (pic1.Top + pic1.Height > pic2.Top) Then
       Intersect = True
     End If
   End If
End Function

If Intersect(Picture1, Picture2) Then ...

Option Explicit

Const a = 0.2
Const b = 0.01
Const bb = 50
Const c = 0.01
Const cc = 100

Private Sub Form_Click()
   Dim x As Single, y As Single, t As Single
    
   For t = 0 To 3500
     x = t * a + Sin(t * b) * bb
     y = Cos(t * c) * cc
     PSet (x, y)
   Next t
End Sub

Private Sub Form_Load()
   ScaleLeft = 0
   ScaleWidth = 500
   ScaleTop = -150
   ScaleHeight = 300
End Sub

Source As Variant

Src As IPicture, ByVal hDC As Long

v=v+f*dt
p=p+v*dt