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3 years ago

Please help :(

1 answer:

7 0

3. A loudspeaker works because of the “motor effect” meaning electricity and a magnetic field cause movement.

4. A direct current will cause momentary movement in one direction only. For the speaker to produce sound you would need alternating current which makes the cone vibrate back & forth.

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Plane polarized light with intensity I0 is incident on a polarizer. What angle should the principle axis make with respenct to t

Nataliya [291]

Answer:

Q = 47.06 degrees

Explanation:

Given:

- The transmitted intensity I = 0.464 I_o

- Incident Intensity I = I_o

Find:

What angle should the principle axis make with respect to the incident polarization

Solution:

- The relation of transmitted Intensity I to to the incident intensity I_o on a plane paper with its principle axis is given by:

I = I_o * cos^2 (Q)

- Where Q is the angle between the Incident polarized Light and its angle with the principle axis. Hence, Using the relation given above:

Q = cos ^-1 (sqrt (I / I_o))

- Plug the values in:

Q = cos^-1 ( sqrt (0.464))

Q = cos^-1 (0.6811754546)

Q = 47.06 degrees

8 0

4 years ago

What energy transformation takes place when an object is pushed up an inclined plane?

Fofino [41]

When you are pushing an object up an inclined plane, the object is gaining gravitational potential energy as it is gaining height. The kinetic energy of the object decreases and converts into that potential energy as you go up. When you have stopped, all of the kinetic energy of the object has fully been converted to gravitational potential energy.

5 0

3 years ago

Read 2 more answers

What is the speed acquired by a freely falling object 4 seconds after being dropped from a rest position? Use units of meter per

gizmo_the_mogwai [7]

speed = 40 m/s

Explanation:

Since the object is dropped, V0y = 0.

Vy = V0y - gt

= -(10 m/s^2)(4 s)

= -40 m/s

This means that its velocity is 40 m/s downwards. Its speed is simply 40 m/s.

6 0

3 years ago

a rugby player passes the ball 5.34 m across the field, where it is caught at the same height as it left his hand. at what angle

MakcuM [25]

Answer:

$31.035^{\circ}$

Explanation:

x = Displacement in x direction = 5.34 m

t = Time taken to travel the displacement

y = Displacement in y direction = 0

u = Initial velocity of ball = 7.7 m/s

g = Acceleration due to gravity = $9.81\ \text{m/s}^2$

Displacement in x direction is given by

$x=u\cos\theta t\\\Rightarrow t=\dfrac{5.34}{7.7 \cos\theta}$

Displacement in y direction is given by

$y=u\sin\theta t-\dfrac{1}{2}gt^2\\\Rightarrow 0=7.7\sin\theta \dfrac{5.34}{7.7\cos\theta}-\dfrac{1}{2}\times 9.81 (\dfrac{5.34}{7.7\cos\theta})^2\\\Rightarrow 0=7.7\sin\theta-4.905\times \dfrac{5.34}{7.7\cos\theta}\\\Rightarrow 0=7.7^2\sin\theta \cos\theta-4.905\times 5.34\\\Rightarrow 0=7.7^2\dfrac{\sin2\theta}{2}-4.905\times 5.34\\\Rightarrow 0=7.7^2\sin2\theta-4.905\times5.34\times 2\\\Rightarrow \sin2\theta=\dfrac{4.905\times 5.34\times 2}{7.7^2}\\\Rightarrow 2\theta=\sin^{-1}\dfrac{4.905\times 5.34\times 2}{7.7^2}$

$\Rightarrow \theta=\dfrac{62.07}{2}\\\Rightarrow \theta=31.035^{\circ}$

The angle at which the ball was thrown is $31.035^{\circ}$ .

7 0

3 years ago

A 37-cm-long wire of linear density 18 g/m vibrating at its second mode, excites the third vibrational mode of a tube of length

lora16 [44]

Answer:

T = 4.42 10⁴ N

Explanation:

this is a problem of standing waves, let's start with the open tube, to calculate the wavelength

λ = 4L / n n = 1, 3, 5, ... (2n-1)

How the third resonance is excited

m = 3

L = 192 cm = 1.92 m

λ = 4 1.92 / 3

λ = 2.56 m

As in the resonant processes, the frequency is maintained until you look for the frequency in this tube, with the speed ratio

v = λ f

f = v / λ

f = 343 / 2.56

f = 133.98 Hz

Now he works with the rope, which oscillates in its second mode m = 2 and has a length of L = 37 cm = 0.37 m

The expression for standing waves on a string is

λ = 2L / n

λ = 2 0.37 / 2

λ = 0.37 m

The speed of the wave is

v = λ f

As we have some resonance processes between the string and the tube the frequency is the same

v = 0.37 133.98

v = 49.57 m / s

Let's use the relationship of the speed of the wave with the properties of the string

v = √ T /μ

T = v² μ

T = 49.57² 18

T = 4.42 10⁴ N

4 0

3 years ago

Read 2 more answers