Answer:v=41.23 m/s
Explanation:
Given
mass of heavy object 
distance of
from the axle 
mass of rock 
Length of rod 
distance of
from axle 
Net torque acting is




Work done by
is converted to rock kinetic Energy
thus

Where 





Answer:
Electrons.
Explanation:
Electricity was discovered before the discovery of electrons by J.J Thompson in 1896. Before the electron, it was thought that it is the positive ions that move through the wire and carry current—that's why today the conventional current represents the flow of positive charges.
After J.J Thompson's discovery of the electrons, it was realized that it is the electrons that actually carry the current through the conductor. But changing the direction of the conventional current didn't seem appropriate, and that's why the convention continues to be used to this day—reminding us that once it were the positive ions that were thought to carry the current.
It is 10.20 m from the ground.
<u>Explanation:</u>
<u>Given:</u>
m = 0.5 kg
PE = 50 J
We know that the Potential energy is calculated by the formula:

where m is the is mass in kg; g is acceleration due to gravity which is 9.8 m/s and h is height in meters.
PE is the Potential Energy.
Potential Energy is the amount of energy stored when an object is stationary.
Here, if we substitute the values in the formula, we get

50 = 0.5 × 9.8 × h
50 = 4.9 × h

h = 10.20 m
Answer:
The perimeter of the rectangle is 60 units.
Explanation:
The perimeter of a rectangle is given by the equation P = 2L + 2W. With W = 12 units and L = 18 units, substituting the values in the equation above:
P = 2(18 units) + 2(12 units)
P = 36 units + 24 units
P = 60 units
Answer:

Option A is correct
Explanation:
Let's check the options:
A: The electron has a negative charge and is found outside of the nucleus.
Yeah! It's TRUE . An electron is a <u>negatively</u><u> </u><u>charged</u><u> </u><u>particle</u><u> </u><u>and</u><u> </u><u>is</u><u> </u><u>located</u><u> </u><u>outside</u><u> </u><u>the</u><u> </u><u>nucleus</u><u> </u><u>of</u><u> </u><u>an</u><u> </u><u>atom.</u>
B : The neutron has a negative charge and is found in the nucleus.
No! It's FALSE . A neutron carries <u>no </u><u>charge</u>. i.e it is a neutral particle and found inside the nucleus.
C : The proton has no charge and is found in the nucleus.
No! It's FALSE.A proton is a <u>positively</u><u> </u><u>charged</u><u> </u><u>particle</u> present inside nucleus of an atom.
D : The neutron has no charge and is found outside of the nucleus.
I agree that the neutron has no charge. But it is found <u>inside</u> the nucleus not outside . So, this statement is FALSE .
Hence, we found our answer! :D
A. The electron has a negative charge and is found outside of the nucleus is the correct statement about an atom.
Hope I helped!
Best regards! :D
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