Answer: 4
The mechanical advantage is the ratio of the force exerted by the object to the force applied to do work on it.
Here, Jeff tried to lift a rock weighing 600 pounds by wedging board under the rock. Jeff who weighs 150 pounds uses all his weight to exert force on lever and lift rock.
Mechanical advantage, 
Therefore, the mechanical advantage that lever provided to Jeff in lifting rock is 4.
Answer:
dissociation of acetic acid (like vinegar) in water
Explanation:
CH3COOH is basically vinegar (aka acetic acid)
dissociation of acetic acid in water
so when you put vinegar in water it makes 2 hydrogen ions (H+) and acetate ( CH3C00 ) a chemical that used in making film
True.
It has been studied in a research study that claims birds have the ability and capability to regenerate their hair cells.
Brainliest please?
Buildings can affect the surface albedo.
The surface is the outermost or uppermost layer of a physical item or area. it is the element or place of the object which could first be perceived by an observer through the usage of the senses of sight and contact and is the component with which other materials first engage.
A surface is the outermost layer of any physical object. it is the part of the object that may be perceived by an observer using their experience of sight and touch and is the portion with which surrounding substances first engage.
The chemical and mechanical residences include chemical composition, grain, hardness, energy, and inhomogeneities.
Learn more about surface here:-brainly.com/question/16519513
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