Answer:
The magnification of an astronomical telescope is -30.83.
Explanation:
The expression for the magnification of an astronomical telescope is as follows;

Here, M is the magnification of an astronomical telescope,
is the focal length of the eyepiece lens and
is the focal length of the objective lens.
It is given in the problem that an astronomical telescope having a focal length of objective lens 74 cm and whose eyepiece has a focal length of 2.4 cm.
Put
and
in the above expression.

M=-30.83
Therefore, the magnification of an astronomical telescope is -30.83.
The slope of a speed-time graph is the acceleration represented by the graph.
All other parts of this question refer to a lab experiment or exercise
where I was not present, but Zeesam16 was. Therefore I have no data
with which to answer the rest of the question, and hope that Zeesam can
handle it.
The period is the time taken by the wave to complete an oscillation. The frequency of the given sound is 500 Hz.
<h2>
Period:</h2>
It is the time taken by the wave to complete an oscillation. The frequency is inversely proportional to the time:

Where,
- frequency
- period = 0.002 s
Put the value in the equation,

Therefore, the frequency of the given sound is 500 Hz.
Learn more about Period:
brainly.com/question/842349
Answer:
1) D
2) A
Explanation:
1) Each group has the same number of valence electrons, which are the outer electrons.
2) Ionic bonds are between a metal and non - metal, the metal being sodium and the non - metal being chlorine.
The can be found elsewhere and as follows:
<span>A. of magnetic effects.
B. the ball tries to pull the rod’s electrons over to it.
C. the rod polarizes the metal.
D. the rod and the ball have opposite charges.
</span><span>
I believe the correct answer is option C. If a negatively charged rod is held near a neutral metal ball, the ball is attracted to the rod. this happens because </span>the rod polarizes the metal. Hope this answers the question.