1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
dexar [7]
3 years ago
6

A 2.0-cm-diameter parallel-plate capacitor with a spacing of 0.50 mm is charged to 200 V?What is the total energy stores in the

electic field?U=______ JWhat is the energy densityu=________J/m^3
Physics
1 answer:
Rama09 [41]3 years ago
7 0

1) 1.11\cdot 10^{-7} J

The capacitance of a parallel-plate capacitor is given by:

C=\frac{\epsilon_0 A}{d}

where

\epsilon_0 is the vacuum permittivity

A is the area of each plate

d is the distance between the plates

Here, the radius of each plate is

r=\frac{2.0 cm}{2}=1.0 cm=0.01 m

so the area is

A=\pi r^2 = \pi (0.01 m)^2=3.14\cdot 10^{-4} m^2

While the separation between the plates is

d=0.50 mm=5\cdot 10^{-4} m

So the capacitance is

C=\frac{(8.85\cdot 10^{-12} F/m)(3.14\cdot 10^{-4} m^2)}{5\cdot 10^{-4} m}=5.56\cdot 10^{-12} F

And now we can find the energy stored,which is given by:

U=\frac{1}{2}CV^2=\frac{1}{2}(5.56\cdot 10^{-12} F/m)(200 V)^2=1.11\cdot 10^{-7} J

2) 0.71 J/m^3

The magnitude of the electric field is given by

E=\frac{V}{d}=\frac{200 V}{5\cdot 10^{-4} m}=4\cdot 10^5 V/m

and the energy density of the electric field is given by

u=\frac{1}{2}\epsilon_0 E^2

and using

E=4\cdot 10^5 V/m, we find

u=\frac{1}{2}(8.85\cdot 10^{-12} F/m)(4\cdot 10^5 V/m)^2=0.71 J/m^3

You might be interested in
A raft with the area A , thickness= h and the mass 600 kg, Floats in still water with 7 cm
elena55 [62]

<span>In this problem, we need to solve for Bubba’s mass. To do this, we let A be the area of the raft and set the weight of the displaced fluid with the raft alone as ρwAd1g and ρwAd2g with the person on the raft, </span>where ρw is the density of water, d1 = 7cm, and d2= 8.4 cm. Set the weight of displaced fluid equal to the weight of the floating objects to eliminate A and ρw then solve for m.

<span>ρwAd1g = Mg</span>

ρw<span>Ad2g = (M + m) g</span>

<span>d2∕d1 = (M + m)/g</span>

m = [(d2<span>∕d1)-1] M = [(8.4 cm/7.0 cm) - 1] (600 kg) =120 kg</span>

This means that Bubba’s mass is 120 kg.

7 0
3 years ago
How can acceleration be described?
krek1111 [17]

Answer:

The definition of acceleration is: Acceleration is a vector quantity that is defined as the rate at which an object changes its velocity. An object is accelerating if it is changing its velocity.

Explanation:

7 0
3 years ago
Read 2 more answers
A 1.0 kg piece of copper with a specific heat of cCu=390J/(kg⋅K) is placed in 1.0 kg of water with a specific heat of cw=4190J/(
Valentin [98]

Answer:

The temperature change of the copper is greater than the temperature change of the water.

Explanation:

deltaQ = mc(deltaT)

Where,

delta T = change in the temperature

m =mass

c = heat capacity

\frac{(deltaT)_{Cu}}{(deltaT)_{w}}=\frac{4190J/kg.K}{390J/kg.K}\\ \\(deltaT)_{Cu}=10.74(deltaT)_{w}

The temperature change in the copper is nearly 11 times the temperature change in the water.

So, the correct option is,

The temperature change of the copper is greater than the temperature change of the water.

Hope this helps!

7 0
3 years ago
A 63 gg ice cube can slide without friction up and down a 30∘30∘ slope. The ice cube is pressed against a spring at the bottom o
tatiyna

Given Information:

slope angle = θ = 30°

spring constant = k = 30 N/m

compressed length = x = 10 cm = 0.10 m

mass of ice cube = m = 63 g = 0.063 kg

Required Information:

distance traveled by ice cube = d = ?  

Answer:

distance traveled by ice cube = 0.48 m

Explanation:

Using the the principle of conversation of energy, the following relation holds true for this case,

mgh = 1/2*kx²

h = 1/2*kx²/mg

Where h is the height of the slope, m is the mass of ice cube, k is the spring constant and x is the compressed length o the spring and g is gravitational acceleration.

h = 1/2*kx²/mg

h = 1/2*30(0.1)²/0.063*9.8

h = 0.242 m

From trigonometry ratio,

sinθ = h/d

d = h/sinθ

d = 0.242/sin(30)

d = 0.48 m

Therefore, when the ice cube is released, it will travel a total distance 0.48 up the slope before reversing direction.

3 0
3 years ago
Is an object moving in uniform circular motion accelerating?
dexar [7]
Yes.

-- 'Acceleration' does NOT mean 'speeding up'.
It means ANY change in the speed OR direction of motion ...
speeding up, slowing down, or turning.

-- If an object is NOT moving in  straight line at constant speed,
then its motion is accelerated.

-- In circular motion, or even just going around a curve,
the object is accelerating, because its direction is constantly
changing, even if its speed is constant.
8 0
3 years ago
Other questions:
  • How do you solve this???
    7·1 answer
  • The property that compares the mass of an object with its volume is _____.
    9·2 answers
  • Which tool is used to track which organisms are carriers of a specific trait through several generations?
    10·2 answers
  • A marble rolls 269cm across the floor with a constant speed of in 44.1cm/s.
    9·1 answer
  • Which letter represents the wavelength of
    7·2 answers
  • A guitar string is fixed at both ends. If you tighten it to increase its tension, the frequencies of its normal modes will incre
    15·1 answer
  • What does a resistor in an electrical dp
    12·1 answer
  • In a coiled spring, the particles of the medium vibrate to and fro about their
    5·1 answer
  • C. If you knew the pressure, volume, and temperature of the air in the
    15·1 answer
  • Solve for the BMI weight 58kg Height 1.61​
    7·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!