Answer:
Explanation:
We define the linear density of charge as:

Where L is the rod's length, in this case the semicircle's length L = πr
The potential created at the center by an differential element of charge is:

where k is the coulomb's constant
r is the distance from dq to center of the circle
Thus.

Potential at the center of the semicircle
Answer:
<u>Conventions used in SI to indicate units are as follows:</u>
- Only singular form of units are used. for example: use kg and not kgs.
- Do not use full stop after the abbreviations of any unit. for example: do not use kg. or cm.
- Use one space between last numeric digit and SI unit. for example: 10 cm, 9 km.
- Symbols and words should not be mixed. for example: use Kilogram per cubic and not kilogram/m3.
- While writing numerals, only the symbols of the units should be written. for example: use 10 cm and not Ten cm.
- Units named after a scientist should be written in small letters. for example: newton, henry.
- Degree sign should not be used when the kelvin unit is used. for exmaple: use 37° and not 37°k
The other nation will get mad at the other nation and they could start a war
................................................................
Answer:
Part a)

Part b)

Explanation:
Since the ball and rod is an isolated system and there is no external force on it so by momentum conservation we will have

here we also use angular momentum conservation
so we have

also we know that the collision is elastic collision so we have

so we have

also we know

also we know

so we have


now we have


Part b)
Now we know that speed of the ball after collision is given as

so it is given as
