A tachometer measures, for example it measures the MPH(Miles Per Hour) in a car. So like it measures your speed, so you could be going 100 MPH.
Explanation:
We start by using the conservation law of energy:
or
Simplifying the above equation, we get
We can rewrite this as
Note that the expression inside the parenthesis is simply the acceleration due to gravity 
so we can write
where 
is the launch velocity.
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Answer:</h2><h3>
<em><u>Alexander Graham Bell</u></em></h3><h2>
Explanation:</h2>
Alexander Graham Bell is often credited as the inventor of the telephone since he was awarded the first successful patent.
Muscles function only by contracting. This makes it necessary for one end of the muscle to be fixed and the other mobile.
Take the bicep for example.
Its origin is at the shoulder and its two heads connect to the bones of the forearm, the radius and ulna.
Now, had the muscle not been fixed at one end, and contracted, it would pull both our shoulder and forearm together resulting in an ineffective movement. The desired motion is to lift the forearm (proximal and distal movement) which can only be achieved if the bicep is fixed at the shoulder and allowed to move at the forearm.
<span>b. becomes weaker
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