Get a one-block tall wall and place two rails connected slantedly. Better powered "Powered Rail". Place a block above the slanted one in which situation this will cut the connection of Redstone. The two rails will not be cut. Run a minecart from the lower rail and see it go through the obstuction.
See MC-42414.
MCPE-6572
Minecart on slanted rails go through blocks
Resolved
Works As Intended
0
iBug Tsun
(Unassigned)
Confirmed
Tablet - iOS - iPad 2
minecart
0.8.0, 0.8.1, 0.9.4, 0.9.5
Retrieved
Hmm... is the same on the PC version, i think Jeb or Notch confirmed that they will not fix it...