800 has 1 significant digit.

A wire of resistance 7 ohms and length 2.8 m is bent into a circle and is concentric with a solenoid in which the magnetic flux

Serggg [28]

Answer:

The emf, electric field and the current in the wire are 10 V, 3.57 V/m and 1.43 A.

Explanation:

Given that,

Resistance = 7 ohms

Length = 2.8 m

Time t =0.2

We need to calculate the change in magnetic flux

Using formula of induced emf

$\epsilon=\dfrac{d\phi}{dt}$

Put the value into the formula

$\epsilon=\dfrac{6-4}{0.2}$

$\epsilon=10\ V$

We need to calculate the electric field in the wire

Using formula of electric field

$E=\dfrac{V}{l}$

$E=\dfrac{10}{2.8}$

$E=3.57\ V/m$

We need to calculate the current in the wire,

Using formula of ohm's law

$V=IR$

$I=\dfrac{V}{R}$

Put the value into the formula

$I=\dfrac{10}{7}$

$I=1.43\ A$

Hence, The emf, electric field and the current in the wire are 10 V, 3.57 V/m and 1.43 A.

7 0

3 years ago

In a manufacturing process, a large, cylindrical roller is used to flatten material fed beneath it. The diameter of the roller i

kotykmax [81]

The maximum angular speed of the roller is 3.47rad/a,

the maximum tangential speed of the point an the rim of the roller is 1.47m/s,

the time t should the driven force be removed from the roller so that the roller does not reverse its direction of rotation is t = 2.78s,

5.4 rotation has the roller turned between t=0 and the time found in part c

<h3>What does tangential speed refer to?</h3>

Any item moving along a circular path has a linear component to its speed called tangential velocity. An object's velocity is always pointed tangentially when it travels in a circle at a distance r from the center. The word for this is tangential velocity.

To calculate the tangential speed, divide the circumference by the time required to complete one spin. For instance, if it takes 12 seconds to complete one rotation, divide 18.84 by 12 to get 1.57 feet per second as the tangential velocity.

(a) angular speed w = dθ/dt = 5t - 1.8t^2

dw/dt = 5 - 3.6t = 0 for max w

so max w occurs at t = 5/3.6 s = 1.39s

so w max = 5*1.39 - 1.8*(1.39)^2 = 3.47 rad/s

(b) tangential speed v = r*w

r = D/2 = 0.5m

so v = 0.5*w = 1.74 m/s

(c) w is positive until 5t = 1.8t^2

so t = 5/1.8s = 2.78s (or t = 0 invalid)

After t = 2.87s, w is negative (starts reversing direction of rotation)

Driving force would actually have to be removed some time before t=2.78s because the roller can't stop instantaneously, but insufficient info to calculate this.

(d) Up to t = 2.78s, θ = 2.5*(2.78)^2 - 0.6*(2.78)^3 rad = 33.95 rad = 5.40 rotations

Therefore,

A) 3.47rad/a

B) 1.47m/s

C) t = 2.78s

D) 5.4 rotation

To learn more about tangential speed, refer to:

brainly.com/question/19660334

#SPJ4

4 0

2 years ago

Two plane waves of the same frequency and with vibrations in the z-direction are given by c (y, t) = (2 cm) cos a p 4 cm y - 20

My name is Ann [436]

The resultant wave at point (5, 2) is Ψ = 5.99 cos [ 7.15 - (20/s) t]

What are the plane waves:

A plane wave is a special case of wave or field: whose value, at any moment, is constant through any plane that is perpendicular to a fixed direction in space.
plane waves are free-space modes.

Here,

Two plane waves are given:

c (5, t) = 4 cos [(8π/3) - (20/s) t]

c (2, t) = 2 cos [(3π/2) - (20/s) t]

now, the waves as imaginary exponentials,

separating the spatial parts, and then adding them together

we get The resultant:

Ψ = [ 4 sin (8π/3) + 2 sin (3π/2) ]^2 + [ 4 cos(8/3 π) + 2 cos(3/2π) ]^2

Ψ = 5.99 tan(a) = 0.747/ 5.95

a = 7.15

Ψ = 5.99 cos [ 7.15 - (20/s) t]

hence,

The resultant wave is Ψ = 5.99 cos [ 7.15 - (20/s) t]

Learn more about Resultant wave here:

<u>brainly.com/question/1190546</u>

#SPJ4

Your question is incomplete, but most probably the full question was:

Two plane waves with the same frequency and with vibrations (measured by Psi) in the z-direction are given by c (x, t) = (4cm.) cos [pi/3cm. x - 20/s t + pi] c (y, t) = (2cm.) cos[pi/4cm. y - 20/s t + pi]

Express the waves as imaginary exponentials, separate the spatial parts, and add them together using a phasor diagram to find the resultant at the point x = 5cm. y = 2cm

4 0

2 years ago

The measure of the force of gravity acting on an object is called

Butoxors [25]

Weight is a measure of the force of gravity acting on an object. According to Newton's laws of motion, force is directly proportional to both mass and acceleration, and the equation for force is F = m * a, where m = mass and a = acceleration.

5 0

4 years ago

In this experiment, you will use a track and a toy car to explore the concept of movement. You will measure the time it takes th

LenKa [72]

A question you can gather from this experiment is figuring out the distance traveled by the car, and how far it went. A simple solve of X equation could be used.

7 0

4 years ago

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