Answer:
a. 11.5kv/m
b.102nC/m^2
c.3.363pF
d. 77.3pC
Explanation:
Data given
to calculate the electric field, we use the equation below
V=Ed
where v=voltage, d= distance and E=electric field.
Hence we have
b.the expression for the charge density is expressed as
σ=ξE
where ξ is the permitivity of air with a value of 8.85*10^-12C^2/N.m^2
If we insert the values we have
c.
from the expression for the capacitance
if we substitute values we arrive at
d. To calculate the charge on each plate, we use the formula below
Answer:
Steps in the order they should occur:
- Observes that there are acidic foods
- Asks a question about food’s acidity
- Creates a hypothesis about the acidity
- Prepares to conduct the experiment
- The student records the acidity of the food.
- Presents the results to the class
Explanation:
This question is addressed to reflect on the scientific method, and so it deals with the logical steps that are followed regularly in such process.
It is the observation of a natural phenomenum what sparks the whole process. In this case, <u><em>the student observes that there are acidic foods</em></u>.
After such observation, some minds, the curious minds, start to ask questions: why?, how?, when?, what happens if? Numerous questions might arise, it is the curiosity attitude, that accompanies the scientific mind. So,<em><u> the student asks a question about food’s acidity</u></em>.
The trained scientist then elaborate a hypothesis : a logical tentative prediction which relates a thesis and a conclusion, in the form if _________ then ________, addresed to answer the question. This hypotheisis must be testable, so it must contains objective variables, which can be verified through an experiment by measurements that can be replicated by any one. So, at this point <em><u>fhe student creates a hypothesis about the acidity</u></em>.
The next steps are:
- <em><u>Prepares to conduct the experiment</u></em>: the student must select the independent, dependent and control variables, and plan the materials and equipment needed, the place, the time, the budget, and the special conditions to perform the experiment.
- <u><em>The student records the acidity of the food</em></u>: the experiment is run and the data is recorded, and analyzed, to drive a conclusion:
- <em><u>Presents the results to the class</u></em>: this is how science evolve. The presentation of the results is important because 1) permits the validation of the results by the community, and 2) permits that other scientist use the results to continue with the process, start with a new question, and, might be, to validate a theory or create a new one.
Answer:
See the answers below.
Explanation:
a) KEf, This term refers to the final kinetic energy i.e. when the velocity has reached 27 [m/s].
To calculate this energy we must use the following equation that relates velocity and mass to kinetic energy.
where:
m = mass = 2.2*10³[kg]
v = velocity = 27 [m/s]
![E_{kin}=\frac{1}{2} *2.2*10^{3}*(27)^{2}\\E_{kin}=801900[J]](https://tex.z-dn.net/?f=E_%7Bkin%7D%3D%5Cfrac%7B1%7D%7B2%7D%20%2A2.2%2A10%5E%7B3%7D%2A%2827%29%5E%7B2%7D%5C%5CE_%7Bkin%7D%3D801900%5BJ%5D)
b)
Power is defined as the amount of energy or work done over a certain time, it can be calculated by means of the following equation.
where:
t = time = 2.4 [s]
P = Power [W]
Now replacing:
![P=801900/2.4\\P=334125[W]\\Now in Hp\\334125[w]*\frac{1hp}{745w} \\= 448.5[hp]](https://tex.z-dn.net/?f=P%3D801900%2F2.4%5C%5CP%3D334125%5BW%5D%5C%5CNow%20in%20Hp%5C%5C334125%5Bw%5D%2A%5Cfrac%7B1hp%7D%7B745w%7D%20%5C%5C%3D%20448.5%5Bhp%5D)
Answer:
15.7 ; 78.5
Explanation:
Given that
The mechanic use a screw driver to install 1⁄4-20 UNC bolt
And, the effort force is 5lb
We need to find out the mechanical advantage
And, the resistance force
As we know that
The Mechanical advantage of a screw = Circumference ÷ pitch
where,
Circumference = pi × d
pi = 3.142, D = diameter
So,
Circumference = 3.142 × (1 ÷ 4)
= 0.785 in
Now
Pitch = 1 ÷ TPI
Here TPI (thread per inch) = 20
Pitch = 1 ÷ 20 = 0.05
So,
Mechanical advantage = 0.785 ÷ 0.05
= 15.7
Now Resistance force if effort force is 5lb
We know that
Mechanical advantage = Fr ÷ Fe
Here
Fe = effort force, Fr = resistance force
15.7 = Fr ÷ 5
Fr = 15.7 × 5
= 78.5 lbs
