The equation of motion of a pendulum is:
where 
it its length and 
is the gravitational acceleration. Notice that the mass is absent from the equation! This is quite hard to solve, but for <em>small</em> angles (
), we can use:
Additionally, let us define:
We can now write:
The solution to this differential equation is:
where 
and 
are constants to be determined using the initial conditions. Notice that they will not have any influence on the period, since it is given simply by:
This justifies that the period depends only on the pendulum's length.
Answer:
<h2>A. Nearsightedness</h2>
Explanation:
A nearsightedness is an eye defect that occurs when someone is only able to see close ranged object but not far distance object. According to the question, if the length of my eye decreases slightly as I age, this means there is a possibility that I will find it difficult to view a far distance object as I age.
At 70, once my eyes had decreased slightly in length, this means I will only be able to see close ranged object but not far distant object, showing that I am now suffering from nearsightedness according to its definition above.
Answer:
V = wavelength * frequency = 1.5 * 5.5 = 8.25 m/s
Velocity includes direction
<span>the body is moving horizontally, it doesnt matter watever kind of horizontal forces are acting.
Therefore the normal force is equal to the weight
N=mg=4.2*9.8=41N
Note: the other data in the problem have no relevance
answer
</span> the normal force on the sled is 41N
