broken/slow minecarts

minecart wont move, minecart was slow, roller coaster un-tested

When I tried to test my roller coaster, I expected to go really fast.
Describe what you thought should happen here

What actually happened was the minecrart didn't move, I put another one down but it moved very slow, even on powered rails

Steps to Reproduce:
1. Place a minecart.
2. Right click it.
3. Hold your "up" key/activate a powered rail/go down hill.