Answer:
The magnitude of angular acceleration is
.
Explanation:
Given that,
Initial angular velocity, 
When it switched off, it comes o rest, 
Number of revolution, 
We need to find the magnitude of angular acceleration. It can be calculated using third equation of rotational kinematics as :
So, the magnitude of angular acceleration is
. Hence, this is the required solution.
What it looks to be that you found in A was the "initial"...b/c the question asks:
<span>"how much energy does the electron have 'initially' in the n=4 excited state?" </span>
<span>"final" would be where it 'finally' ends up at, ie. its last stop...as for this question...the 'ground state' as in its lowest energy level. </span>
The answer comes to: <span>−1.36×10^−19 J</span>
You use the same equation for the second part as for part a.
<span>just have to subract the 2 as in the only diff for part 2 is that you use 1squared rather than 4squared & subract "final -initial" & you should get -2.05*10^-18 as your answer. </span>
Answer with Explanation:
We are given that
Resistivity of copper wire=
Diameter=d=
Radius of copper wire=
Radius of solenoid=r'
1 m=100 cm
a.Length of wire=l=11.3 m
Area of wire=A=
Where 
A=
Resistance, R=
Using the formula


B.Length of solenoid=
m
Number of turns=
=60
C.Potential difference,V=3 V
Current,I=
I=
D.Total length =0.1 m
Number of turns per unit length,n=
Magnetic field along central axis inside of the solenoid,B=

After three half-lives have elapsed, the amount of an 8.0 g sample of a radionuclide that remains undecayed is 1.0 g.
<h3>What is Half-Life?</h3>
Half-Life refers to the time it takes for half the amount of a substance to disappear or change.
The nucleus of the atoms of radioactive elements disintegrate to half their starting amounts after every Half-Life.
After three half-lives one-eight of the original atoms remain.
Therefore, after three half-lives have elapsed, the amount of an 8.0 g sample of a radionuclide that remains undecayed is 1.0 g.
Learn more about Half-Life at: brainly.com/question/26689704
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Given:
The mass of the copper cylinder is: m = 76.8 g = 0.0768 kg
The change in the temperature is: T = 86.5 deg C - 19.5 deg C = 67 deg C
The specific heat is: c = 0.092 cal/g.C
To find:
Heat energy needed to heat the copper cylinder.
Explanation:
The specific heat is defined as the amount of heat energy needed to raise the temperature of a substance by one degree celcius.
The expression relating heat Q, mass m, specific heat c and temperature difference T is:

Substitute the values in the above equation, we get:

Final answer:
473.40 calories of heat is required to heat the copper cylinder.