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
Temka [501]
3 years ago
14

Two trains are traveling on the same track and in the same direction. The first train, which is behind the second train, blows a

horn whose frequency is 269 Hz. The second train detects a frequency of 290 Hz. If the speed of the second train is 13.7 m/s, what is the speed of the first train?
Physics
1 answer:
Andrews [41]3 years ago
5 0

Answer:

37.545 m/s

Explanation:

f' = Actual frequency of horn = 269 Hz

f = Observed frequency of horn = 290 Hz

v = Speed of sound in air = 343 m/s

v_0 = Speed of second train = 13.7 m/s

v_s = Speed of first train

From Doppler effect we have

f=f'\dfrac{v-v_0}{v-v_s}\\\Rightarrow v_s=v-\dfrac{f'}{f}(v-v_0)\\\Rightarrow v_s=343-\dfrac{269}{290}(343-13.7)\\\Rightarrow v_s=37.545\ m/s

The speed of the first train is 37.545 m/s

You might be interested in
From what does oil form?
Akimi4 [234]
C dinosaurs. Once they break down and get pressurized they turn to oil
6 0
3 years ago
Which statements describe a physical property of matter? Check all that apply. A cumulus cloud is puffy and white. Vinegar has a
JulsSmile [24]
<span>A cumulus cloud is puffy and white.
</span><span>Vinegar has a very sour smell.
</span><span>Water boils at 100 degrees Celsius. </span>
4 0
3 years ago
Read 2 more answers
10. Hamilton How long does it take Lewis travelling at 156 m.p.h to cover 16 miles?
Anvisha [2.4K]

Answer: Hello!

Lewis is travelling at 165 mph, which means miles per hour, this says that he does 165 miles in one hour.

We want to know how much time takes to cover 16 miles.

this can be calculated as the quotient of the distance and the velocity; this is:

t = \frac{16 mi}{165 mi/h} = 0.096 h

if we want to write this in minutes, then:

we know that one hour has 60 minutes, then 0.096 hours has:

0.096h*60mins/1h = 5.8 minutes.

then Lewis needs 5.8 minutes in order to cover 16 miles if his speed is 156 miles per hour.

6 0
3 years ago
Read 2 more answers
A bucket of water of mass 10 kg is pulled at constant velocity up to a platform 30 meters above the ground. This takes 10 minute
Rudik [331]

Answer:

W = 2352 J

Explanation:

Given that:

  • mass of the bucket, M = 10 kg
  • velocity of pulling the bucket, v = 3m.min^{-1}
  • height of the platform, h = 30 m
  • time taken, t = 10 min
  • rate of loss of water-mass, m = 0.4 kg.min^{-1}

Here, according to the given situation the bucket moves at the rate,

v=3 m.min^{-1}

The mass varies with the time as,

M=(10-0.4t) kg

Consider the time interval between t and t + ∆t. During this time the bucket moves a distance

∆x =  3∆t meters

So, during this interval change in work done,

∆W = m.g∆x

<u>For work calculation:</u>

W=\int_{0}^{10} [(10-0.4t).g\times 3] dt

W= 3\times 9.8\times [10t-\frac{0.4t^{2}}{2}]^{10}_{0}

W= 2352 J

5 0
3 years ago
A boat heads due North for 3.00 km to reach a red buoy. It then changes direction and heads in a direction of 30.0 degrees South
Helga [31]

Position of B :  

x = 4.66*cos 30 = 4.036  

y = 3-4.66*sin 30 = 3-2.33 = 0.67  

BC = √y^2+(x-1)^2 = √0.67^2+3.036^2 = 3.109  

heading = arctan y/(x-1) = arctan 0.67/(3.036) = 12.44° south of west

hope this helps :)

6 0
3 years ago
Other questions:
  • A spherical balloon is 40 ft in diameter and surrounded by air at 60°F and 29.92 in Hg abs.(a) If the balloon is filled with hyd
    6·2 answers
  • The pattern of repeating properties of elements revealed in the periodic table is known as the (Blank)
    15·2 answers
  • A wheel rotates with a constant angular acceleration of  rad/s2. During a certain time interval its angular displacement is  r
    7·1 answer
  • After brainstorming, engineers may refine their ideas by making what???
    12·1 answer
  • Which statements about cirrus clouds are true? Choose all answers that are correct. A. Cirrus clouds form high in the sky. B. Ci
    14·2 answers
  • Jasmine is diving off a 3-meter springboard. her height in meters above the water when she is x meters horizontally from the end
    6·1 answer
  • I NEED THIS ASAP
    5·1 answer
  • A gas undergoes a process in a piston–cylinder assembly during which the pressure-specific volume relation is pv1.1 = constant.
    10·1 answer
  • A particle of mass 10 g and charge 72 μC moves through a uniform magnetic field, in a region where the free-fall acceleration is
    7·1 answer
  • When you push a toy car it eventually stops this is due to something called
    15·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!