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
Minchanka [31]
3 years ago
12

A circular loop of flexible iron wire has an initial circumference of 161 cm , but its circumference is decreasing at a constant

rate of 11.0 cm/s due to a tangential pull on the wire. The loop is in a constant uniform magnetic field of magnitude 0.800 T , which is oriented perpendicular to the plane of the loop. Assume that you are facing the loop and that the magnetic field points into the loop.
Physics
1 answer:
miss Akunina [59]3 years ago
7 0

Complete question is;

A circular loop of flexible iron wire has an initial circumference of 161 cm , but its circumference is decreasing at a constant rate of 11.0 cm/s due to a tangential pull on the wire. The loop is in a constant uniform magnetic field of magnitude 0.800 T , which is oriented perpendicular to the plane of the loop. Assume that you are facing the loop and that the magnetic field points into the loop.

Find the emf induced in the loop, at the instant when 9.0s has passed.

Answer:

Magnitude of EMF induced = 0.008686 V

Explanation:

We are given;

Initial circumference; C = 161 cm

rate of decrease of circumference; dC/dt = 11 cm/s

magnetic field; B = 0.8 T

time; t = 9 sec

To find emf in loop, we'll use the formula;

EMF = -d(BAcosθ)/dt

Now, we are told magnetic field is uniform, thus angle is zero.

Thus;

EMF = -d(BAcos0)/dt

cos 0 = 1

Thus;

EMF = -B(dA/dt)

so area will be

Area of the loop is (πr²)

Thus;

dA/dt = d(πr²)/dt

Differentiating with respect to r, we have;

dA/dt = 2πr(dr/dt)

Formula for circumference is;

C = 2πr

Making r the subject, we have;

r = C/2π

Thus;

R = 161/2π

r = 25.6239 cm

c is circumference so from equation 2

From EMF = -B(dA/dt) , let's replace dA/dt with 2πr(dr/dt) since dA/dt = 2πr(dr/dt)

Thus;

EMF = -2πrB(dr/dt)

From C = 2πr, we can derive the rate of increase in radius.

Thus;

dC/dt = 2π(dr/dt)

Plugging in the relevant values, we have;

dr/dt = 11/2π = 1.75 cm/s

At the instance when 9 s has passed, radius of the could is now;

r1 = r - 9(dr/dt)

r1 = 25.6239 - 9(1.75)

r1 = 9.8739 cm

We will need to plug in 0.8 for B, 9.8739 cm for r, 1.75 cm/s for dr/dt into;

EMF = -2πrB(dr/dt)

But, we have to convert cm to m.

Thus: 9.8739 cm = 9.8739 × 10^(-2) m

1.75 cm = 0.0175 m

Thus;

EMF = -2π × 9.8739 × 10^(-2) × 0.8 × 0.0175

EMF = -0.008686 V

For magnitude of emf, we will take the absolute value.

Thus;

Magnitude of EMF = 0.008686 V

You might be interested in
A hollow sphere of radius 0.200 m, with rotational inertia I = 0.0484 kg·m2 about a line through its center of mass, rolls witho
d1i1m1o1n [39]

Answer:

Part a)

KE_r = 8 J

Part b)

v = 3.64 m/s

Part c)

KE_f = 12.7 J

Part d)

v = 2.9 m/s

Explanation:

As we know that moment of inertia of hollow sphere is given as

I = \frac{2}{3}mR^2

here we know that

I = 0.0484 kg m^2

R = 0.200 m

now we have

0.0484 = \frac{2}{3}m(0.200)^2

m = 1.815 kg

now we know that total Kinetic energy is given as

KE = \frac{1}{2}mv^2 + \frac{1}{2}I\omega^2

KE = \frac{1}{2}mv^2 + \frac{1}{2}I(\frac{v}{R})^2

20 = \frac{1}{2}(1.815)v^2 + \frac{1}{2}(0.0484)(\frac{v}{0.200})^2

20 = 1.5125 v^2

v = 3.64 m/s

Part a)

Now initial rotational kinetic energy is given as

KE_r = \frac{1}{2}I(\frac{v}{R})^2

KE_r = \frac{1}{2}(0.0484)(\frac{3.64}{0.200})^2

KE_r = 8 J

Part b)

speed of the sphere is given as

v = 3.64 m/s

Part c)

By energy conservation of the rolling sphere we can say

mgh = (KE_i) - KE_f

1.815(9.8)(0.900sin27.1) = 20- KE_f

7.30 = 20 - KE_f

KE_f = 12.7 J

Part d)

Now we know that

\frac{1}{2}mv^2 + \frac{1}{2}I(\frac{v}{r})^2 = 12.7

\frac{1}{2}(1.815) v^2 + \frac{1}{2}(0.0484)(\frac{v}{0.200})^2 = 12.7

1.5125 v^2 = 12.7

v = 2.9 m/s

8 0
3 years ago
Your cat "Ms." (mass 7.00 {\rm kg}) is trying to make it to the top of a frictionless ramp 2.00 {\rm m} long and inclined upward
lbvjy [14]

Answer:

Final velocity at the top of the ramp is 6.58m/s

Explanation

Check the attachment

4 0
3 years ago
1.Predict the frequency of a tuning fork that emits a sound with a wavelength of 0.385 m.
lina2011 [118]

Answer:

1.) Frequency F = 890.9 Hz

2.) Wavelength (λ) = 0.893 m

Explanation:

1.) Given that the wavelength = 0.385m

The speed of sound = 343 m / s

To predict the frequency, let us use the formula V = F λ

Where (λ) = wavelength = 0.385m

343 = F × 0.385

F = 343/0.385

F = 890.9 Hz

2.) Given that the frequency = 384Hz

Using the formula again

V = F λ

λ = V/F

Wavelength (λ) = 343/384

Wavelength (λ) = 0.893 m

The two questions can be solved with the use of formula

3 0
3 years ago
at which plate boundary would you expect to see volcanoes A.divergent b.all of the above c.convergent D.transform
natulia [17]
A or d would be most likely it
7 0
3 years ago
A planet has a circular orbit around a star. It is a distance of 53,000,000 km from the centre of the star.
Kipish [7]

Answer:

it takes 365 days to revolve around the star(sun)

5 0
3 years ago
Other questions:
  • The number ocean waves that pass a buoy in one second is _ of the wave
    11·2 answers
  • Which best describes the relationship between population size, carrying capacity, and limiting factors?
    5·2 answers
  • A bee flies forward at 4.9m/s for 48s , lands on a flower and stays there for 28s , then flies back along its previous route at
    12·1 answer
  • A compass originally points North; at this location the horizontal component of the Earth's magnetic field has a magnitude of 2e
    12·1 answer
  • True or False?
    12·2 answers
  • HELPPP MEEEEEE PLEASEEEE
    10·1 answer
  • In one of the classic nuclear physics experiments at the beginning of the 20th century, alpha particles were accelerated toward
    9·1 answer
  • These two waves travel along the same string: y1 = (4.17 mm) sin(2.24?x - 300?t), y2 = (5.96 mm) sin(2.24?x - 300?t + 0.727?rad)
    12·1 answer
  • You are in a car and go around a corner very fast. What happens to you?
    14·1 answer
  • How would you rate your mental health from a scale of 1 (lowest) to 5 (highest) and why?
    12·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!