Fluke don't contain bones, while fins do. Flukes go fast while fins steer. Flukes also manage temperature control.
The simple answer is that in a battery the chemical reactions that produce the electrical current are produced from materials that are already in the battery itself, whereas in a fuel cell, the reactants, almost always Hydrogen and Oxygen are fed to the cell like an external fuel.
. However, while a battery makes electricity from the energy it has stored inside the battery, a fuel cell makes its electricity from fuel in an external fuel tank This means that while a battery may run dead, a fuel cell will make electricity as long as fuel is supplied. For hydrogen fuel cells, hydrogen is the fuel and it's stored in a tank connected to the fuel cell. When hydrogen in the tank runs low, you refill it, or replace it with a full tank.
Answer:
3 materials
Explanation:
The jacket and trousers worn by a firefighter have to be constructed from materials that will withstand intense heat. Aramid fiber is a synthetic fiber that is highly regarded for its strength and heat resistance. Nomex is the trade name for arimid fiber clothing, and this type of material is used in the construction of a firefighter jacket and trousers. Nomex is often combined with Kevlar to increase the strength of the material.