Answer:
3. velocity is zero.
Explanation:
The velocity of a simple harmonic motion is given by

Here, <em>ω</em> is the angular velocity, <em>A</em> is the amplitude (or maximum displacement from the equilibrium point) and <em>x</em> is the displacement at any time.
At maximum displacement, <em>x </em>=<em> A</em>.<em> </em>Then

Therefore, at maximum displacement, velocity is 0.
Practically, this can be observed in a simple pendulum. As it approaches the maximum displacement, its velocity reduces. It becomes zero at this point and then reverses as the pendulum changes course. Then the velocity begins to increase. It becomes maximum at the equilibrium point but once past that, the velocity begins to reduce as it approaches the other amplitude.
For acceleration,

It follows that at maximum displacement, the acceleration is a maximum. The negative sign indicates that it is in an opposite direction to the displacement. Both kinetic energy (
) and linear momentum (
) are proportional to velocity; they are therefore both zero at the maximum displacement.
(BELOW YOU CAN FIND ATTACHED THE IMAGE OF THE SITUATION)
Answer:

Explanation:
For this we're going to use conservation of mechanical energy because there are nor dissipative forces as friction. So, the change on mechanical energy (E) should be zero, that means:
(1)
With
the initial kinetic energy,
the initial potential energy,
the final kinetic energy and
the final potential energy. Note that initialy the masses are at rest so
, when they are released the block 2 moves downward because m2>m1 and finally when the mass 2 reaches its maximum displacement the blocks will be instantly at rest so
. So, equation (1) becomes:
(2)
At initial moment all the potential energy is gravitational because the spring is not stretched so
and at final moment we have potential gravitational energy and potential elastic energy so
, using this on (2)
(3)
Additional if we define the cero of potential gravitational energy as sketched on the figure below (See image attached),
and we have by (3) :
(4)
Now when the block 1 moves a distance d upward the block 2 moves downward a distance d too (to maintain a constant length of the rope) and the spring stretches a distance d, so (4) is:

dividing both sides by d


, with k the constant of the spring and g the gravitational acceleration.
Given data
*The given 4th harmonic frequency is 31.5 Hz
The fundamental frequency is calculated as

Hence, the fundamental frequency is 7.875 Hz
<h2>Answer: Francium
</h2>
Let's start by explaining that electronegativity is a term coined by Linus Pauling and is determined by the <em>ability of an atom of a certain element to attract electrons when chemically combined with another atom.
</em>
So, the more electronegative an element is, the more electrons it will attract.
It should be noted that this value can not be measured directly by experiments, but it can be determined indirectly by means of calculations from other atomic or molecular properties of the element. That is why the scale created by Pauling is an arbitrary scale, where the maximum value of electronegativity is 4, assigned to Fluorine (F) and the <u>lowest is 0.7, assigned to Francium (Fr).</u>