Given Information:
Inductance = L = 5 mH = 0.005 H
Time = t = 2 seconds
Required Information:
Current at t = 2 seconds = i(t) = ?
Energy at t = 2 seconds = W = ?
Answer:
Current at t = 2 seconds = i(t) = 735.75 A
Energy at t = 2 seconds = W = 1353.32 J
Explanation:
The voltage across an inductor is given as
The current flowing through the inductor is given by
Where L is the inductance and i(0) is the initial current in the inductor which we will assume to be zero since it is not given.
![i(t) = \frac{1}{0.005} \int_0^t \mathrm{5(1-e^{-0.5t}}) \,\mathrm{d}t \,+ 0\\\\i(t) = 200 \int_0^t \mathrm{5(1-e^{-0.5t}}) \,\mathrm{d}t \\\\i(t) = 200 \: [ {5\: (t + \frac{e^{-0.5t}}{0.5})]_0^t \\i(t) = 200\times5\: \: [ { (t + 2e^{-0.5t} + 2 )] \\](https://tex.z-dn.net/?f=i%28t%29%20%3D%20%5Cfrac%7B1%7D%7B0.005%7D%20%5Cint_0%5Et%20%5Cmathrm%7B5%281-e%5E%7B-0.5t%7D%7D%29%20%5C%2C%5Cmathrm%7Bd%7Dt%20%5C%2C%2B%200%5C%5C%5C%5Ci%28t%29%20%3D%20200%20%5Cint_0%5Et%20%5Cmathrm%7B5%281-e%5E%7B-0.5t%7D%7D%29%20%5C%2C%5Cmathrm%7Bd%7Dt%20%5C%5C%5C%5Ci%28t%29%20%3D%20200%20%5C%3A%20%5B%20%7B5%5C%3A%20%28t%20%2B%20%5Cfrac%7Be%5E%7B-0.5t%7D%7D%7B0.5%7D%29%5D_0%5Et%20%5C%5Ci%28t%29%20%3D%20200%5Ctimes5%5C%3A%20%5C%3A%20%5B%20%7B%20%28t%20%2B%202e%5E%7B-0.5t%7D%20%2B%202%20%29%5D%20%5C%5C)
So the current at t = 2 seconds is
The energy stored in the inductor at t = 2 seconds is
Answer: 33.35 minutes
Explanation:
A(t) = A(o) *(.5)^[t/(t1/2)]....equ1
Where
A(t) = geiger count after time t = 100
A(o) = initial geiger count = 400
(t1/2) = the half life of decay
t = time between geiger count = 66.7 minutes
Sub into equ 1
100=400(.5)^[66.7/(t1/2)
Equ becomes
.25= (.5)^[66.7/(t1/2)]
Take log of both sides
Log 0.25 = [66.7/(t1/2)] * log 0.5
66.7/(t1/2) = 2
(t1/2) = (66.7/2 ) = 33.35 minutes
Answer:
165 mm
Explanation:
The mass on the piston will apply a pressure on the oil. This is:
p = f / A
The force is the weight of the mass
f = m * a
Where a in the acceleration of gravity
A is the area of the piston
A = π/4 * D1^2
Then:
p = m * a / (π/4 * D1^2)
The height the oil will raise is the heignt of a colum that would create that same pressure at its base:
p = f / A
The weight of the column is:
f = m * a
The mass of the column is its volume multiplied by its specific gravity
m = V * S
The volume is the base are by the height
V = A * h
Then:
p = A * h * S * a / A
We cancel the areas:
p = h * S * a
Now we equate the pressures form the piston and the pil column:
m * a / (π/4 * D1^2) = h * S * a
We simplify the acceleration of gravity
m / (π/4 * D1^2) = h * S
Rearranging:
h = m / (π/4 * D1^2 * S)
Now, h is the heigth above the interface between the piston and the oil, this is at h1 = 42 mm. The total height is
h2 = h + h1
h2 = h1 + m / (π/4 * D1^2 * S)
h2 = 0.042 + 10 / (π/4 * 0.14^2 * 0.8) = 0.165 m = 165 mm
A8 is the answer because yea and because I am a teacher
Answer:
I'm going to make a list of everything you need to consider for the supervision and design of the bridge.
1. the materials with which you are going to build it.
2. the length of the bridge.
3. The dynamic and static load to which the bridge will be subjected.
4. How corrosive is the environment where it will be built.
5.wind forces
6. The force due to possible earthquakes.
7. If it is going to be built in an environment where snow falls.
8. The bridge is unique,so the shape has a geometry that resists loads?.
9. bridge costs.
10. Personal and necessary machines.
11. how much the river grows
