ball bearings and lubrication.
with hockey tape
No its not
Roller blades are much faster and better. The roller skates are not as flexible as roller blades are. It's much safer to wear roller blades than roller skates and roller skates are likely to trip you up than roller blades. Also roller blades have more control than roller skates.
It keeps the roller down and creates friction to allow the roller to move.
Roller blading is an incredibly popular recreational activity, and as such there are numerous types of roller blades on the market. The type of roller blades you should buy depends on your goals and where you plan to use them. Read on for information on the most common types of roller blades and how to go about finding the best ones for you. If you plan to use your roller blades for simple skating, such as around a park or on the sidewalk, look for a pair of recreational roller blades. These in-line skates have basic features and made for those who are new to roller blading. If you plan to play hockey with your roller blades, you will need to find a pair that are more functional. Look for sleek, lightweight blades that will increase your speed while playing. Note that many roller blades designed for roller hockey do not have a brake system. You should also search for roller blades that are durable and can withstand the punishment of the sport. Hockey blades usually have lace-up fronts and smaller wheels than traditional roller blades. If you plan to do aggressive roller blading, look for what are known as stunt blades. Stunt blades are designed for more extreme bladers who plan to do tricks with their roller blades. Stunt blades are frequently used in skate parks and on half pipes. They are usually very durable and lightweight for easy maneuverability. Lastly, women should look for a pair of roller blades made specifically for them. Women's roller blades usually have thinner wheels and a higher arch than men's blades. They are also cut lower in the back to properly fit women's calves. Regardless of the style of roller blades you buy, be sure to buy a set of high-quality wheels. Roller blade wheels are measure by their hardness, with each being provided a number between 70 and 78. The higher the number, the harder the wheel.
There are a lot of good sites for Roller blades. One that I prefer is Rollerwarehouse.com they have a lot to choose from in many different sizes. They also have many other things besides roller blades.
Roller Coasters. roller coasters are affected by rolling friction (hence roller) not sliding
Roller rocker arms perform the same function as standard rocker arms. Mainly, they are the mechanical link between the push rod and the valves. Roller rockers are better because they have a cylindrical roller that reduces noise and friction instead of simply having a flat spot directly contacting the top of the valve.