Answer:
a, 1.775s
b, 17.04μC
c, 1.28s
Explanation:
Given
R = 1.25MΩ
C = 1.42µF
ε = 12.0 V
q = 8.78 µC
Time constant, τ = RC
τ = (1.25*10^6) * ( 1.42*10^-6)
τ = 1.775s
q• = εC
q• = 12 * 1.42*10^-6
q• = 17.04*10^-6C
q• = 17.04μC
Time t =
q = q• [1 - e^(t/τ)]
t = τIn[q•/(q•-q)]
t = 1.775In[17.04μC/(17.04μC-8.78μC)]
t = 1.775In(2.06)
t = 1.775*0.723
t = 1.28s
Answer:
ωi = 15.4 rev/sec
Explanation:
Since the movement of the fan is rotating, we are thus dealing with Rotational motion. In rotational motion, for angular speed to take place also means angular acceleration is also occurring.
angular acceleration = α = (change in speed)/(change in time)
angular acceleration = α = Δw/Δt = (ω - ωi) /(t- t₀) ..........(equation 1)
α = (ω -ωi) /(t- 0)
α = (ω-ωi) /t
ωi = ω - αt ......................................(equation 2)
where ωi is the initial angular speed.
We replace the values for ω, t and α
ωi = 105 rad/sec - ( 4.4 rad/sec² )(1.85s) = 96.86 rad/s = 15.415747788 rev/sec
Answer:

Explanation:
From the question, using the expression:

where;



This is a combined intensity of 4 speakers.
Thus, the intensity of 3 speakers = 
= 2.372 W/m²
Thus;


Answer:
Mass of the steel cube = 7800 kg
Volume of the steel = 1.025 cubic centimetre
Explanation:
Given:
The density of the steel = 7.8
Side of the cube = 12 cm
<u>(1)The mass of steel cube :</u>
We know that,

We are given with density and sides of the cube
then volume of the cube
=
= 
= 1000 cubic centimetre
Now


mass = 7800 kg
<u>(2)volume of steel:</u>
Given the mass = 8 kg

Substituting the values


volume = 1.025 cubic centimetre