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4 years ago

A spinning coil of wire is what moves the cone in a speaker, producing the sound. True/False

Physics

2 answers:

valentina_108 [34]4 years ago

6 0

Answer:

False

Explanation:

Georgia [21]4 years ago

5 0

False, the spinning coil of wire that moves the cone in a speaker does not produces sound.

Explanation:

The wire coil is an electromagnet that is fixed to speaker cone. A normal magnet attached to the back of the speaker cone.When audio is sent in the form of short bursts of electric current to the speaker cone through the wire.

A magnetic field is induced when electric current allowed to pass through the coil. This magnetic field is repelled by the other magnet. This repulsion cause the cone to move forward. In the absence of electric current in the coil, the cone moves backward.

Thus sound waves are produced due to the resulting rarefaction and compression. So it is not the spinning coil of wire but he permanent magnet that produces the sound.

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The name of the Sl unit for force is the ___? A. Joule B. Newton C.Watt

tiny-mole [99]

Answer:

the name of the SI unit for force is the newton

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3 years ago

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If a force is 100 N and is pointing 37 degrees north of east. (a) Draw a diagram of this force. (b) Draw the force's x and y com

sasho [114]

Answer

given,

force = 100 N

Point 37 degrees north of east

a) and b) part is shown in the diagram attached below.

c) to find the x and y component of the force

x- component of the force

$F_x = F cos \theta$

$F_x = 100\times cos 37^0$

$F_x = 79.86 N$

y- component of the force

$F_y = F sin \theta$

$F_y = 100\times sin 37^0$

$F_y = 60.18 N$

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3 years ago

A jewellery melts 500g of Silver to pour into a mould. Calculate how much energy was released as the silver solidified.

irga5000 [103]

When silver is poured into the mould the it will solidify

In this process the phase of the Silver block will change from liquid to solid.

This phase change will lead to release in heat and this heat is known as latent heat of fusion.

The formula to find the latent heat of fusion is given as

$Q = mL$

here given that

$m = mass = 500 g$

$L = 111 kJ/kg$

now we can find the heat released

$Q = 0.5 * 111 kJ$

$Q = 55.5 kJ$

So it will release total heat of 55.5 kJ when it will solidify

8 0

4 years ago

A bicycle wheel rotates at a constant 25 rev/min. What is true about its angular acceleration?

Nostrana [21]

Answer:

The angular acceleration is zero

Explanation:

When an object is in rotational motion, it has a certain angular velocity, which is the rate of displacement of its angular position.

This angular velocity can change or remain constant - this is given by the angular acceleration, which is:

$\alpha =\frac{\Delta \omega}{\Delta t}$

where

$\Delta \omega$ is the change in angular velocity

$\Delta t$ is the time elapsed

Therefore, the angular acceleration is the rate of change of angular velocity.

In this problem, the bicycle rotates at a constant angular velocity of

$\omega=25 rev/min$

This means that the change in angular velocity is zero:

$\Delta \omega=0$

And so, that the angular acceleration is zero:

$\alpha=0$

8 0

3 years ago

A 1 kg mass is attached to a spring with spring constant 7 Nt/m. What is the frequency of the simple harmonic motion? What is th

Scorpion4ik [409]

1. 0.42 Hz

The frequency of a simple harmonic motion for a spring is given by:

$f=\frac{1}{2\pi}\sqrt{\frac{k}{m}}$

where

k = 7 N/m is the spring constant

m = 1 kg is the mass attached to the spring

Substituting these numbers into the formula, we find

$f=\frac{1}{2\pi}\sqrt{\frac{7 N/m}{1 kg}}=0.42 Hz$

2. 2.38 s

The period of the harmonic motion is equal to the reciprocal of the frequency:

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

where f = 0.42 Hz is the frequency. Substituting into the formula, we find

$T=\frac{1}{0.42 Hz}=2.38 s$

3. 0.4 m

The amplitude in a simple harmonic motion corresponds to the maximum displacement of the mass-spring system. In this case, the mass is initially displaced by 0.4 m: this means that during its oscillation later, the displacement cannot be larger than this value (otherwise energy conservation would be violated). Therefore, this represents the maximum displacement of the mass-spring system, so it corresponds to the amplitude.

4. 0.19 m

We can solve this part of the problem by using the law of conservation of energy. In fact:

- When the mass is released from equilibrium position, the compression/stretching of the spring is zero: $x=0$ , so the elastic potential energy is zero, and all the mechanical energy of the system is just equal to the kinetic energy of the mass:

$E=K=\frac{1}{2}mv^2$

where m = 1 kg and v = 0.5 m/s is the initial velocity of the mass

- When the spring reaches the maximum compression/stretching (x=A=amplitude), the velocity of the system is zero, so the kinetic energy is zero, and all the mechanical energy is just elastic potential energy:

$E=U=\frac{1}{2}kA^2$

Since the total energy must be conserved, we have:

$\frac{1}{2}mv^2 = \frac{1}{2}kA^2\\A=\sqrt{\frac{m}{k}}v=\sqrt{\frac{1 kg}{7 N/m}}(0.5 m/s)=0.19 m$

5. Amplitude of the motion: 0.44 m

We can use again the law of conservation of energy.

- $E_i = \frac{1}{2}kx_0^2 + \frac{1}{2}mv_0^2$ is the initial mechanical energy of the system, with $x_0=0.4 m$ being the initial displacement of the mass and $v_0=0.5 m/s$ being the initial velocity

$- E_f = \frac{1}{2}kA^2$ is the mechanical energy of the system when x=A (maximum displacement)

Equalizing the two expressions, we can solve to find A, the amplitude:

$\frac{1}{2}kx_0^2 + \frac{1}{2}mv_0^2=\frac{1}{2}kA^2\\A=\sqrt{x_0^2+\frac{m}{k}v_0^2}=\sqrt{(0.4 m)^2+\frac{1 kg}{7 N/m}(0.5 m/s)^2}=0.44 m$

6. Maximum velocity: 1.17 m/s

We can use again the law of conservation of energy.

$- E_f = \frac{1}{2}mv_{max}^2$ is the mechanical energy of the system when x=0, which is when the system has maximum velocity, $v_{max}$

Equalizing the two expressions, we can solve to find $v_{max}$ , the maximum velocity:

$\frac{1}{2}kx_0^2 + \frac{1}{2}mv_0^2=\frac{1}{2}mv_{max}^2\\v_{max}=\sqrt{\frac{k}{m}x_0^2+v_0^2}=\sqrt{\frac{7 N/m}{1 kg}(0.4 m)^2+(0.5 m/s)^2}=1.17 m/s m$

4 0

3 years ago

Read 2 more answers