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
lidiya [134]
2 years ago
5

The label has been scratched off a tuning fork and you need to know its frequency. From its size, you suspect that it is somewhe

re around 250 Hz. You find a 250-Hz tuning fork and a 270-Hz tuning fork. When you strike the 250-Hz fork and the fork of unknown frequency, you hear a modulation (fluctuation of the amplitude) at a frequency of 5 Hz. When you strike the unknown with the 270-Hz fork, you hear a modulation at a frequency of 15 Hz. What is the unknown frequency
Physics
1 answer:
bonufazy [111]2 years ago
3 0

Answer:

255 Hz

Explanation:

With 5 beats per second with the 250 Hz fork, we know the unknown fork is either 250 - 5 = 245Hz or 250 + 5 = 255 Hz

With 15 beats per second with the 270 Hz fork, we know the unknown fork is either 270 - 15 = 255Hz or 270 + 15 = 285 Hz (most people would have a hard time discerning 15 beats per second... 5 per second is hard enough)

As 255 is the common frequency, it is the one selected.

You might be interested in
A modern compact fluorescent lamp contains 1.4 mg of mercury (Hg). If each mercury atom in the lamp were to emit a single photon
Reika [66]

Answer:

A. 1.64 J

Explanation:

First of all, we need to find how many moles correspond to 1.4 mg of mercury. We have:

n=\frac{m}{M_m}

where

n is the number of moles

m = 1.4 mg = 0.0014 g is the mass of mercury

Mm = 200.6 g/mol is the molar mass of mercury

Substituting, we find

n=\frac{0.0014 g}{200.6 g/mol}=7.0\cdot 10^{-6} mol

Now we have to find the number of atoms contained in this sample of mercury, which is given by:

N=n N_A

where

n is the number of moles

N_A=6.022\cdot 10^{23} mol^{-1} is the Avogadro number

Substituting,

N=(7.0\cdot 10^{-6} mol)(6.022\cdot 10^{23} mol^{-1})=4.22\cdot 10^{18} atoms

The energy emitted by each atom (the energy of one photon) is

E_1 = \frac{hc}{\lambda}

where

h is the Planck constant

c is the speed of light

\lambda=508 nm=5.08\cdot 10^{-7}nm is the wavelength

Substituting,

E_1 = \frac{(6.63\cdot 10^{-34} Js)(3\cdot 10^8 m/s)}{5.08\cdot 10^{-7} m}=3.92\cdot 10^{-19} J

And so, the total energy emitted by the sample is

E=nE_1 = (4.22\cdot 10^{18} )(3.92\cdot 10^{-19}J)=1.64 J

4 0
3 years ago
if a pressure of 70.kPa on a volume of 80.cm cubed is reduced to 10.kPa, by what factor does the pressure change
boyakko [2]

70-10/70 x 100  percentage change ....

60/70, 6/7 fract change


6 0
3 years ago
Please help me feel out this paper. Very hard for me to figure thu
Anastaziya [24]
Tension is the force causing the path. It is always directed inward for circular motion. To hit the ceiling you need B. The stopper will travel along the tangent line it was moving when released (when tension goes to 0). This is upward in B so it will keep going up to the ceiling.
The velocity is pointed along the tangent line at all times (parallel to the edge of the circle at any point)
5 0
3 years ago
A mixture of gas expands from 0.03m³ to 0.06m³ at constant pressure of 1MPa & absorbs energy of 84 J. Calculate the change i
leonid [27]

Answer:54 kj

Explanation:P1 = P2 = 1000 kPa

1Q2 = 84 kJ

1W2 = P1 (V2 – V1)

= 1000 (0.06 – 0.03) = 30 kJ

1Q2 = 1W2 + 1U2

U2 – U1= 1Q2 – 1W2 = 84 – 30 = 54 kJ

4 0
2 years ago
How do we use information from earths climate change data in order to engineer soulutions that reduce carbon emissions and impac
masya89 [10]

Answer:

That is a very broad question. One thing that does not seem to be considered is the depletion of the ozone layer at high altitudes.

In the 1960's chlorofluorcarbons (CFC,s) became popular as refrigerants, spray can propellants, etc.  In January 1989 the Montreal Protocol was passed which has greatly reduced the use of these substances. However, it may be several decades before the ozone layer can be replaced and again absorb harmful ulraviolet rays that may be partly responsible for the increase in global warming.  

(One chlorine atom at high altitudes can be responsible for the destruction of 100,000 molecules of ozone - catalytic reaction)

7 0
2 years ago
Other questions:
  • In a shot-put competition, a shot moving at 15m/s has 450J of mechanical kinetic energy. What is the mass of the shot? Please he
    7·1 answer
  • When something could pose a danger, this could be a...
    13·2 answers
  • A rock with a mass of 25 kg has a weight of 40.8 n on the moon. what is the value of the acceleration of gravity (g) on the moon
    14·1 answer
  • My brainly won’t load please help it’s glitching and saying “oops, something went wrong”
    14·1 answer
  • In the system illustrated by the diagram, the magnetic field is increasing. In which
    10·1 answer
  • Two objects of different mass rest on Earth. Which one experiences the greater acceleration due to gravity ?
    5·1 answer
  • A ball is thrown into the air with an upward velocity of 20 feet per second. Its height, h, in feet after t seconds is given by
    11·1 answer
  • What is the energy level of hydrogen?
    10·1 answer
  • John flies directly east for 20km, then turns to the north and flies for another 10 km before dodging a flock of geese. what’s t
    12·1 answer
  • IF YOU ANSWER THESE 3 QUESTIONS! I WILL GIVE YOU BRAINEST!!! 17 POINTS!!!
    14·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!