Answer:
8, 8 W
Explanation:
The useful power of 1 Light Emitting Diode is

Total power required is 1.6 W
Number of Light Emitting Diodes would be

The number of Light Emitting Diodes is 8.
Power would be

The power that is required to run the Light Emitting Diodes is 8 W
Answer:
Since the spring mass system will execute simple harmonic motion the position as a function of time can be written as
'A' is the amplitude = 6 inches (given)
is the natural frequency of the system
At equilibrium we have

Applying values we get

thus natural frequency equals

Thus the equation of motion becomes

At time t=0 since mass is at it's maximum position thus we have

Thus the position of mass at the given times is as follows
1) at

2) at

3) at

4) at

5) at

Answer:
5.1*10^3 J/m^3
Explanation:
Using E = q/A*eo
And
q =75*10^-6 C
A = 0.25
eo = 8.85*10^-12
Energy density = 1/2*eo*(E^2) = 1/2*eo*(q/A*eo)^2 = [q^2] / [2*(A^2)*eo]
= [(75*10^-6)^2] / [2*(0.25)^2*8.85*10^-12]
= 5.1*10^3 J/m^3
So the equation for angular velocity is
Omega = 2(3.14)/T
Where T is the total period in which the cylinder completes one revolution.
In order to find T, the tangential velocity is
V = 2(3.14)r/T
When calculated, I got V = 3.14
When you enter that into the angular velocity equation, you should get 2m/s
Ordinary cells can convert chemical energy to electrical energy only, but rechargeable cells can also store electrical energy into chemical energy and vice versa. You will study more about it in your higher classes. secondary cells can be recharged and used again but dry cells cannot be recharged.