if you are talking about a plant that used to have leaves and lost them, than the now leafless plant loses (or has water travel faster through it) than with leaves, if you are talking about plants that are always leafless (cacti) it isn't faster than leaf plant because they store their water better so it moves very slowly in cacti.
The denser the faster. ie: it will travel faster through quartz than sandstone.
sound travel faster through soled because of tighter packed particles
Waves travel faster through denser materials. However, Electromagnetic waves travel faster through less dense materials. It travels fastest in vacuum.
Light travels much faster than sound, through wood.
Yes. Also through leaves.
Sound
Air.
15 times faster
sound travels faster through water than air.
no sound travels faster through solids.
I believe that sound travels faster through iron because it bounces off the sides, and causes it to travel faster, reaching the other side.
Sound waves travel faster through denser media, like solids, because the molecules are closer together, making it easier to pass the sound from molecule to molecule. Light and other electromagnetic waves travel faster through less dense media, and they travel fastest through a vacuum.