1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
Anon25 [30]
3 years ago
7

If two firecrackers produce a sound level of 81 dBdB when fired simultaneously at a certain place, what will be the sound level

if only one is exploded?
Physics
1 answer:
Mrac [35]3 years ago
5 0

Answer:

77.96dB

Explanation:

Recall that decibels are a unit of measuring intensity of sound, and depend on the logarithm of the intensity

the intensity, measured in decibels is given by:

I(db)=10log(I/I0)

I is the intensity in MKS units; I0 is the threshold intensity for human hearing (10^-12 W/m^2)

Thus, if the two sounds together have a dB of 81, we know:

81=10log(I/I0)

using the data above, we can find the intensity of the two sounds to be

0.000125 W/m^2

therefore, one firecracker has an intensity half of that, or 0.0000625W/m^2

now use this value to find the dB of one firecracker:

I(dB0=10log(0.0000625/10^-12)=77.96dB

You might be interested in
Please help soon!!!!
anyanavicka [17]
The Answer: Parallel
6 0
3 years ago
Read 2 more answers
help me pass the test please there is a couple of questions in my profile to answer i am leaving this one for you to help ​
kompoz [17]

Answer:

0.5 m/s².

Explanation:

From the question given above, the following data were obtained:

Initial velocity (u) = 0 m/s

Final velocity (v) = 10 m/s

Time (t) = 20 s

Acceleration (a) =?

Acceleration can simply be defined as the rate of change of velocity with time. Mathematically, it is expressed as:

a = (v – u) / t

Where:

a is the acceleration.

v is the final velocity.

u is the initial velocity.

t is the time.

With the above formula, we can obtain the acceleration of the car as follow:

Initial velocity (u) = 0 m/s

Final velocity (v) = 10 m/s

Time (t) = 20 s

Acceleration (a) =?

a = (v – u) / t

a = (10 – 0) / 20

a = 10/20

a = 0.5 m/s²

Therefore, the acceleration of the car is 0.5 m/s².

6 0
3 years ago
Parasaurolophus was a dinosaur whose distinguishing feature was a hollow crest on the head. The 1.3 m long hollow tube in the cr
yarga [219]

Answer:

67.31 Hz, 201.92 Hz, 336.54 Hz

Explanation:

Resonance also known as standing wave occur when a uniform tube is closed at one end and open at the other end.  

For a resonance wave in a tube with length b, wavelength λ of resonance wave is 4b because a quarter wave is formed in the tube, that is,  

           λ = 4b.  

When the speed of sound is c, the frequency of sound, f, is  

           f = c /λ,  

and therefore,  

           f = c / ( 4b ).  

From the question,

When c = 350 m/s and b = 1.3 m,  

using the formula            

fn = c / ( 4b ) × n (n = 1, 3, 5, ...).  

The first three resonant frequencies are;

First resonance frequency is

f = 350 / (4*1.3) * 1 = 67.31 Hz

Second resonance frequency is

f = 350 / (4*1.3) * 3 = 201.92 Hz

Third resonance frequency is

f = 350 / (4*1.3) * 5 = 336.54 Hz

5 0
4 years ago
A steel ball is dropped to a wood table. What are three ways in which energy is wasted when the ball bounces?
hodyreva [135]

Answer:1. Inelastic deformation of wood and steel

2.thermal energy: hear from wood and steel

3.acoustic energy

Explanation:

6 0
3 years ago
Imagine a leaf floating down a creek (south) at a rate of 6m/s. You walk in the creek towards the leaf (north) at a rate of 2m/s
Juli2301 [7.4K]

It depends on what is the reference frame where the velocity of the leaf (6 m/s) is measured.

If it is measured with respect to the creek, then the answer is simply "6 m/s south".

If it is measured with respect to the observer moving toward the leaf, then the velocity of the leaf relative to the ground is actually the sum between the velocity of the leaf relative to the observer (6 m/s south, so 6 m/s) and the velocity of the observer relative to the ground (2 m/s north, so -2 m/s):

v=v_l +v_o =6 m/s +(-2 m/s)=4 m/s

and the direction is south.

8 0
3 years ago
Other questions:
  • Assume that the average mass of each of the approximately 1 billion people in China is 55 kg.Assume that they all gather in one
    10·1 answer
  • Which statement is true for light passing into a medium that is more optically dense than the first medium through which it past
    14·1 answer
  • (a) Calculate the self-inductance (in mH) of a 55.0 cm long, 10.0 cm diameter solenoid having 1000 loops.
    14·1 answer
  • A 0.0450-kg golf ball initially at rest is given a speed of 25.0 m/s when a club strikes. If the club and ball are in contact fo
    7·1 answer
  • Would electromagnetic waves exist if changing magnetic fields could produce electric fields but changing electric fields could n
    11·1 answer
  • A positive charge, q1, of 5 µC is 3 × 10–2 m west of a positive charge, q2, of 2 µC. What is the magnitude and direction of the
    14·2 answers
  • a 2.0-mole sample of an ideal gas is gently heated at constant temperature 330 k. it expands from initial volume 19 l to final v
    15·1 answer
  • Moon A has a mass of 3M and a radius of 2R. Moon B has a mass of 4M and a radius of R. What is the ratio of the force of gravita
    6·1 answer
  • Why is no image formed when an object is at the focal point of a converging lens?
    9·1 answer
  • A child is stationary on a swing.(a)The child is given a push by his brother to start him swinging.His brother applies a steady
    12·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!