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.
Answer with Explanation:
We are given that


Charge on proton,q=
a.We have to find the electric potential of the proton at the position of the electron.
We know that the electric potential

Where 


B.Potential energy of electron,U=
Where
Charge on electron
=Charge on proton
Using the formula


The time needed for the hammer to reach the surface of the Earth is 3.54 s.
<h3>
Time of motion of the hammer</h3>
The time of motion is calculated as follows;
t = √(2h/g)
where;
- h is height of fall
- g is acceleration due to gravity
t = √(2 x 10 / 1.6)
t = 3.54 s
Thus, the time needed for the hammer to reach the surface of the Earth is 3.54 s.
Learn more about time of motion here: brainly.com/question/2364404
#SPJ1
Answer:
b.it depends on the distance it falls
Answer:
Explanation:
height of pole = 15 ft
height of man = 6 ft
Let the length of shadow is y .
According to the diagram
Let at any time the distance of man is x.
The two triangles are similar

15 y - 15 x = 6 y
9 y = 15 x

Differentiate with respect to time.

As given, dx/dt = 4 ft/s

ft/s