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
AleksAgata [21]
3 years ago
7

A rifle is fired in a valley with parallel vertical walls. The echo from one wall is heard 1.55 s after the rifle was fired. The

echo from the other wall is heard 2.5 s after the first echo. How wide is the valley? The velocity of sound is 343 m/s. Answer in units of m.
Physics
1 answer:
elena55 [62]3 years ago
6 0

Answer:

w=694.575\ m

Explanation:

Given:

velocity of the sound, v=343\ m.s^{-1}

time lag in echo form one wall of the valley, t= 1.55\ s

time lag in echo form the other wall of the valley, t'=2.5\ s

<u>distance travelled by the sound in the first case:</u>

d=v.t

d=343\times 1.55

d=531.65\ m

Since this is the distance covered by the sound while going form the source to the walls and then coming back from the wall to the source so the distance of the wall form the source will be half of the distance obtained above.

s=\frac{d}{2}

s=\frac{531.65}{2}

s=265.825\ m

<u>distance travelled by the sound in the second case:</u>

d'=v.t'

d'=343\times 2.5

d'=857.5\ m

Since this is the distance covered by the sound while going form the source to the walls and then coming back from the wall to the source so the distance of the wall form the source will be half of the distance obtained above.

s'=\frac{d'}{2}

s'=\frac{857.5}{2}

s'=428.75\ m

<u>Now the width of valley:</u>

w=s+s'

w=265.825+428.75

w=694.575\ m

You might be interested in
Determine the lamp wattage required to obtain an illumination level of 50 f-c over a 100 ft2 area if a fixture is used with a CU
Bezzdna [24]

Lamp Wattage is utilized with a CU of 0.75 and 80 percent of the available light reaches the work surface, the remaining 20 percent is absorbed by walls and other objects in the space, resulting in an illumination level of 50 f-c over a 100 ft2 area

The term "lumen" refers to the emission of "luminous flux," which is a measurement of the total amount of visible light emitted by a source in a certain amount of time. The illumination level over a 100 ft2 area will be 50 f-c Lamp Wattage with a CU of 0.75 used, with 80 percent of the available light reaching the work surface and the remaining 20 percent being absorbed by walls and other objects in the room.
Total Lamp Wattage = Number of Lamps X Wattage of Each Lamp.
The fixtures' total wattage is 2 x 32, or 64 watts.
Lumen per Fixtures equals Lumen Efficiency (Lumen per Watt) times the Watt of each Fixture
85x 64 = 5440 lumens per fixture.

To learn more about lamp wattage please visit -
brainly.com/question/27154431
#SPJ4

3 0
2 years ago
An 67-kg jogger is heading due east at a speed of 2.3 m/s. A 70-kg jogger is heading 61 ° north of east at a speed of 1.3 m/s. F
ololo11 [35]

Answer

given,

mass of jogger  = 67 kg

speed in east direction = 2.3 m/s

mass of jogger 2 = 70 Kg

speed  = 1.3 m/s  in  61 ° north of east.

jogger one

P_1 = m_1 v_1 \hat{i}

P_1 = 67 \times 2.3\hat{i}

P_1 = 154.1 \hat{i}

P_2 = m_2 v_2 \hat{i} +m_2 v_2 \hat{j}

P_2 = 70\times v cos \theta \hat{i} +70\times v sin \theta \hat{j}

P_2 = 70\times 1.3 cos 61^0 \hat{i} +70\times 1.3 sin 61^0\hat{j}

P_2 = 44.12\hat{i} +79.59\hat{j}

now

P = P₁ + P₂

P = 198.22 \hat{i} +79.59 \hat{j}

magnitude

P = \sqrt{198.22^2 + 79.59^2}

P =213.60 kg.m/s

\theta = tan^{-1}\dfrac{79.59}{198.22}

\theta = 21.87

the angle is \theta = 21.87 north of east

7 0
3 years ago
The X-ray source Cygnus X-1 has a mass of at least 11 solar masses and a diameter of only about one-quarter the diameter of the
SOVA2 [1]

Answer:

Answer is It was deduced from the rate at which it glimmers.

Refer below.

Explanation:

The X-ray source Cygnus X-1 has a mass of at least 11 solar masses and a diameter of only about one-quarter the diameter of the Earth. With such a small diameter it must be a compact object, and with such a large mass it can't be a white dwarf or a neutron star, so a black hole is the only possibility remaining. The diameter of Cygnus X-1 found:

It was deduced from the rate at which it glimmers.

7 0
3 years ago
Mamie clark was a psychologist who is known for her research on ?
koban [17]

Mamie Phipps Clark is a noted woman psychologist, best known for her research on race, self-esteem, and child development. Her work alongside her husband, Kenneth Clark, was critical in the 1954 Brown vs Board of Education case and she was the first black woman to earn a degree from Columbia University.

4 0
3 years ago
Read 2 more answers
A student pushes against a wall with a force of 30N. The wall does not move. What amount of force does the wall exert on the stu
True [87]

Answer:

C

Explanation:

they both have to be the same for both to not move

8 0
2 years ago
Read 2 more answers
Other questions:
  • The total energy of a 0.050 kg object travelling at 0.70 c is:
    8·2 answers
  • A 5510 kg space probe, moving nose-first toward Jupiter at 250 m/s relative to the Sun, fires its rocket engine, ejecting 75.0 k
    7·1 answer
  • Convection can occur in which two substances?
    11·2 answers
  • Do all planetary systems look the same as our own?
    7·1 answer
  • A 1.5 in diameter solid shaft is made of a steel alloy having an allowable shear stress of �allow = 12 ksi. a) Determine the max
    14·1 answer
  • A particular gun (10kg) is able to fire 20 gram bullets at a speed of 350 m/s. From this information, calculate roughly how much
    15·1 answer
  • When dropping a grape and a bowling ball from a height, the force of gravity would be identical on each object. True or False
    9·2 answers
  • Between which of the following surfaces would the force of friction be
    9·1 answer
  • speedy drives horizontally off a clif with a velocity of 15 m/s. he lands 30m from the base of the cliff. how high is the cliff?
    8·1 answer
  • An installation consists of a 30-kVA, 3-phase transformer, a 480-volt primary, and a 240-volt secondary. Calculate the largest s
    12·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!