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3 years ago

Which of the following is the most important difference between a permanent magnet and a electromagnet

Physics

1 answer:

Ira Lisetskai [31]3 years ago

5 0

Answer:

Explanation: the major difference between an electromagnet and permanent magnet is that the former can have a magnetic field when electric current flows through it and disappears when the flow of the current stops. ... It will always displays the magnetic behaviour.

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When gamma radiation is released by an atom,. A) it is the only radiation emitted. B) it only ever accompanies beta radiation. C

Sidana [21]

Hello!

The gamma radiation haven't mass or charge. When it is released, it usually accompanies beta or alpha radiation. Letter d).

Hugs!

7 0

3 years ago

Read 2 more answers

In the javelin throw at a track-and-field event, the javelin is launched at a speed of 29 m/s at an angle of 36???? above the ho

netineya [11]

Answer:

t = 0.96 s is the time it takes for the angle to reduce

Explanation:

In the launch of projectiles, the velocity is broken down into its x and y components, the velocity in the x-axis is constant, as there is no acceleration, instead the velocity in the axis and is reduced by the effect of the acceleration of gravity.

We can find Vox for the initial conditions

Voy = Vo sin θ

Voy = 29 sin 36

VoY = 17 m/s

Vox = Vo cos θ

Vox = 29 cos 36

Vox= 23.5 m/s

Vx = Vox

The velocity on the x axis is constant

By trigonometry, we find the firing angle

tan θ = Voy/ Vx

Vy = Vx tan θ

Vy = 23.5 tan 18

Vy = 7.64 m/s

Now that we have the vertical speed we can find the time

Vy = I'm going - g t

t = (Vy -Voy) / g

t = (17 - 7.64) /9.8

t = 0.96 s

Be the time it takes for the angle to reduce

6 0

4 years ago

While watching some tv you see a circus show in which a woman drives a motorcycle around the inside of a vertical ring. you dete

Mila [183]

Since the biker is moving at constant speed

so we will have

$v = \frac{distance}{time}$

here we know that

$distance = 2\pi R$

time = 4 second

now we have

$v = \frac{2\pi R}{4} = \frac{\pi R}{2}$

now at the top point it feels free fall

so it is

$mg = \frac{mv^2}{R}$

$v^2 = Rg$

$(\frac{\pi R}{2})^2 = Rg$

$R = \frac{4g}{\pi^2}$

so height of the bike at the top is same as diameter

$h = 2R$

$h = \frac{8g}{\pi^2} = 7.95 meter$

Yes it will hurt on falling from this height

5 0

4 years ago

OSCilloscope shows wave starts cycle minimum 20 units reaches max of 100 units before completing 5 milliseconds what is relation

Vitek1552 [10]

Answer:

$T=0.02\ s$

$f=50\ Hz$

Explanation:

Given:

minimum amplitude at the start of oscillation cycle, $a_0=20\ unit$

the first maximum amplitude after the start of oscillation cycle, $a_{m1}=100\ units$

Time taken to reach from the first minima to the first maxima, $t=5\times 10^{-3}\ s$

As we know that an oscilloscope executes a wave cycle represented by a sine wave. So we can deduce that it has executed one-fourth of the cycle in going from the amplitude of 20 units to 100 units in 0.005 seconds.

So the time taken to complete one cycle of the oscillation:

$T=4\times 0.005$

$T=0.02\ s$ is the time period of the oscillation

We know frequency:

$f=\frac{1}{T}$

$f=\frac{1}{0.02}$

$f=50\ Hz$

6 0

4 years ago

Who did not have experimental evidence to support his theory of the atom? Dalton Thomson Rutherford Democritus

Aloiza [94]

Democritus was the one who did not have experimental evidence to support his theory of the atom.

Answer: Option 4

Explanation:

The discovery of atoms were first stated by Democritus but due to the absence of any experimental proof, his statement was not noted as significant at that time.

After this, Dalton made the specific assumptions formulating some postulates for the atomic theory with proof. Then the cathode rays tube experiments performed by Thomson lead to the formation of plum pudding models of atom.

This is followed by Rutherford’s gold foil experiment discovering the presence of nucleus inside the atoms. So, Democritus first stated but due to absence of experimental evidences, his theory of atoms were not supported at that time.

3 0

3 years ago