Invented by Archimedes around 250 BC, a Block is a set of pulleys on an axle in a housing. When rope is run through a block or a series of blocks, the whole assembly is called a Tackle. The most common arrangement is to have one1 block attached to a fixed position and another block left to move with the load being pulled or lifted. The mechanical advantage of a block and tackle is equal to the number of time the same line is attached to or runs through the moving block. The pulley on the left does not have a block on the Bale. When you pull on the rope, you are pulling the full weight of the bail. The tackle on the right has 4 lines running through its pulleys. This would allow you to lift 20 pounds with only about 5 pounds of pressure on the hauling part of the line. While the block and tackle is still used today, it has been largely replaced with the electric winch.
The rope used in the 1800's would have been of natural fiber like we have in this exhibit. The rope around the bail is made of SISAL which comes from the leaves of the agave plant. Cotton rope is running in the blocks. Notice how soft it is compared to the SISAL fiber rope. Jute fiber twine, from the Corchorus plant, is used to tie the ends of the larger ropes. It is the same fiber woven to make burlap sacks. Natural fiber rope continued to be in widespread use until the 1950s when synthetic fibers, such as nylon, became popular.
Answer:
Covering organs within trunk cavities
Lining trunk cavities
Explanation:
Serous membranes are layers of tissue that protect the organs. They prevent the organs from getting damage from friction which can occur as they rub against the cavity walls.
Serous membranes have two layers, the visceral layer and the parietal layer. The visceral layer covers the organs while the parietal layer covers or lines the cavity walls. In between these two layers, you will find a gap or cavity filled with serous fluid.
They cover organs like the heart, lungs, blood vessels (some of them at least), testes and other organs found in the abdominal cavity.
Different types of fish live for different amount of times. For example, Bettas live up to two years, Loaches live u to 10 years, and Goldfish live for a few or many decades. Most of the average fish don't live up as long as they could.
My source: Goggle.com.
I truly hope this helped!
Answer:
Touch
Explanation:
<em>Because your body will consist of skin at first which will have receptors and neurones to give you the feeling of feeling something when you touch it</em> hence touch is what you develop as a first sense
