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Anit [1.1K]
3 years ago
13

a sound intensity of 70 dB is observed a distance of d from the source of sound. what sound intensity would be observed at a dis

tance 2d from the source
Physics
1 answer:
elixir [45]3 years ago
5 0

Answer:

Correct option is

B

16dB

Sound level at A is ⊥o⊥B

If the intensity of sound at A 4 cm away from the source is I

A

then.

⊥o=10log

I

o

I

A

Where I

o

=10

−12

w m

−2

⇒⊥=log

10

−12

I

A

⇒

10

−12

I

A

=10

⇒I

A

=10

−11

wm

−2

If the source (s) is emmitting the sound energy of power P

I

A

=

4×(4)

2

P

⇒P=10

−11

×64π w

⇒ Intensity of sound (I

B

) ar point B,2 m

I

B

=

4π(2)

2

P

I

B

=

16π

64π×10

−11

10 m

−2

⇒I

B

=4×10

−11

wm

−2

⇒ Sound level at 2m=10log(

I

I

B )

=10log(10 −12

4×10 −11)

=10log40

=16.02

Hence Sound level at 2m from sourceis 16 dB

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Natalija [7]

Answer:

c. Only the linear acceleration is zero.

Explanation:

The linear acceleration is defined as the rate of change of linear velocity. Since the bicycle is moving in the same direction, with the same speed, without speeding up or slowing down. Therefore, there will be no change in linear velocity and as a result, linear acceleration will be zero.

The angular acceleration is the rate of change of angular velocity. Since the angular velocity is changing its direction constantly. Therefore, it has a certain component of acceleration at all times called centripetal acceleration.

Therefore, the correct option is:

<u>c. Only the linear acceleration is zero.</u>

4 0
2 years ago
The voltage across the terminals of a 9.0 v battery is 8.5 v when the battery is connected to a 60 ω load. part a what is the ba
snow_lady [41]
Refer to the diagram shown below.

i = the current in the circuit., A
R₁ = the internal resistance of the battery, Ω
R₂ = the resistance of the 60 W load, Ω

Because the resistance across the battery is 8.5 V instead of 9.0 V, therefore
(R₁ )(i A) = 9 - 8.5 = (0.5 V)
R₁*i = 0.5         (10

Also,
R₂*i = 9.5         (2)

Because the power dissipated by R₂ is 60 W, therefore
i²R₂ = 60
From (2), obtain
i*9.5 = 60
i = 6.3158 A

From (1), obtain
6.3158*R₁ = 0.5
R₁ = 0.5/6.3158 = 0.0792 Ω = 0.08 Ω (nearest hundredth)

Answer: 0.08 Ω

3 0
2 years ago
Read 2 more answers
A 0.5 m diameter wagon wheel consists of a thin rim having a mass of 7 kg and six spokes, each with a mass of 1.2 kg. 1.2 kg 7 k
Arte-miy333 [17]

Explanation:

It is given that,

Mass of the rim of wheel, m₁ = 7 kg

Mass of one spoke, m₂ = 1.2 kg

Diameter of the wagon, d = 0.5 m

Radius of the wagon, r = 0.25 m

Let I is the the moment of inertia of the wagon wheel for rotation about its axis.

We know that the moment of inertia of the ring is given by :

I_1=m_1r^2

I_1=7\times (0.25)^2=0.437\ kgm^2

The moment of inertia of the rod about one end is given by :

I_2=\dfrac{m_2l^2}{3}

l = r

I_2=\dfrac{m_2r^2}{3}

I_2=\dfrac{1.2\times (0.25)^2}{3}=0.025\ kgm^2

For 6 spokes, I_2=0.025\times 6=0.15\ kgm^2

So, the net moment of inertia of the wagon is :

I=I_1+I_2

I=0.437+0.15=0.587\ kgm^2

So, the moment of inertia of the wagon wheel for rotation about its axis is 0.587\ kgm^2. Hence, this is the required solution.

4 0
3 years ago
Fill in the blanks with suitable pronouns.
DaniilM [7]

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4. Ravina isn't well. Dad is taking to the doctor. (No personal pronouns required)

<h3>5. My sister is a teacher. \bf\underline{She}She teaches Maths.</h3>

7 0
3 years ago
ONLY TWO ANSWER CHOICES!!
Otrada [13]
A: Buoyant force is equal to the weight
3 0
3 years ago
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