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:
particulate hypothesis of inheritance
Explanation:
This states that the inheritable factors retain their identity generation after generation.
Cocaine induces a sense of exhilaration by increasing the availability of dopamine and serotonin in synapses. Cocaine is among the powerful stimulants which increase the release of neurotransmitters such as nor-epinephrine, dopamine and serotonin, that affect CNS and PNS activity. Cocaine administration constricts blood vessels that are absorbing it, son snorting it is a slow way to deliver it to blood stream and eventually the brain.
Answer:
<u>Too much heat can disrupt subcellular structures such as membrane proteins, and enzymes while damaging the integrity of the plasma membrane.</u>
Explanation:
Proteins are macromolecules made up of amino acids. These fold and bond to form several biologically important molecules. For instance, enzymes, a special type of protein functions by <em>providing alternative reaction pathways. They work best at a specific pH and </em><em>optimal temperature range</em><em>, beyond which they become non-functional or denatured entirely. </em>
The denaturing of proteins occur at high temperatures, and alter protein folding, bonding and other types of behavior. Furthermore, membrane proteins are important for regulating cell function. If these are disrupted, the system cannot maintain homeostasis i.e a constant internal environment.
The dummy down way definition of anatomy is the internal workings of animals, humans or plants.
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