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
Bad White [126]
3 years ago
8

A high speed train is traveling at a speed of 44.7 m/s when the engineer sounds the 415 Hz warning horn. The speed of sound is 3

43 m/s. What is the wavelength of the sound, as perceived by the person standing at a crossing when the train is a) approaching and b) find the frequency when leaving the crossing?
Physics
1 answer:
il63 [147K]3 years ago
8 0

Answer:

Explanation:

Speed of the source of sound = v = 44.7 m/s

Speed of sound = V = 343 m/s

a) Apparent  frequency as the train approaches = f =  [V /(V -v) ] × f

= [343 / (343 - 44.7) ] × 415  = 477.18 Hz

Wave length =  λ = v / f = 343 / 477.18 = 0.719 m

b) Frequency heard as the train leaves = f ' =  [V / ( V + v) ] f

                                                                     = [343 / { 343 + 44.7 ) ] x 415

                                                                      = 367.2 Hz

Wavelength when leaving = v / f = 343 / 367.2 = 0.934 m

You might be interested in
Please help it’s easy will give brainlist !! Thank youu worth a lot be serious pls
Genrish500 [490]

Answer:

Part 1

Stationary

Part 2

20 Newtons

Part 3

Force

Part 4

4.0 m/s²

Part 5

Normal

Part 6

Cart m

Part 7

The gravitational force is less than magnetic force

Explanation:

Part 1

The position time graph of the object is an horizontal straight line passing across the top of the position 3 boxes vertically up from the origin

As the time increases by the units of number boxes to the left, the position of the object does not change and remains at the 3 boxes up above the origin, therefore, the object is stationary

Part 2

By Newton's third law of motion, the action action obtained from a force is equal to the reaction given to the force, therefore, we have;

The force exerted by the student on the scale = The force exerted by the scale on the student = 20 N

Part 3

A force is a the directional push on an object or pull from the object as a form of interaction with another object which tends to alter or maintain the motion of the object

Part 4

The given parameters are'

The mass of block A = 1.0 kg

The mass of block B = 2.0 kg

Both blocks, "A" and "B" are initially at rest

The applied horizontal force, F = 12-N

The nature of the surface over which the blocks move = Smooth surface

Force, F = Mass, m × Acceleration, a

F = m × a

The blocks two blocks experience a common acceleration, a

The combined mass of the two blocks, m = 1.0 kg + 2.0 kg = 3.0 kg

m = 3.0 kg

Therefore, a = F/m = 12-N/(3.0 kg) = 4 m/s²

Part 5

A normal force is a force acting perpendicularly to a surface that supports the weight of an object

Part 6

The given parameters are;

M = 2 kg

The mass of the left cart attached to the spring = M = 2 kg

The mass of the right cart attached to the spring = 2·M = 2 × 2 kg = 4 kg

Therefore, given that the force exerted by one cart on the other after the spring is removed, we have;

Force, F = M × a₁ = 2·M × a₂

Where;

a₁ = The average acceleration of the cart with mass, M

a₂ = The average acceleration of the cart with mass, 2·M

M × a₁ = 2·M × a₂

∴ a₁ = 2·a₂

The acceleration, a₁, of car M = 2 × The acceleration, a₂, of car 2·M

The acceleration of cart M is two times the acceleration of cart 2·M

Cart M will experience a greater average acceleration

Part 7

For the top magnet of two magnets placed two magnets arranged so that one is on top the other, to be held in the air with a space between the two magnets, the gravitational force pulling the top magnet down, is less than the repelling magnetic force between the two magnets.

7 0
3 years ago
What makes a substance, such as<br> aluminum, a good conductor?
spin [16.1K]

Answer:

For a material to be a good conductor, the electricity passed through it must be able to move the electrons; the more free electrons in a metal, the greater its conductivity.

8 0
2 years ago
You do 20 J of work pushing a crate up a ramp. If the output work from the inclined plane is 11 J, then what is the efficiency o
fomenos

Answer:

55%

Explanation:

take efficiency=power output/power input multiply by 100%

5 0
3 years ago
A place kicker must kick a football from a point 36.0 m (about 40 yards) from the goal. half the crowd hopes the ball will clear
trapecia [35]
<span>The ball clears by 11.79 meters Let's first determine the horizontal and vertical velocities of the ball. h = cos(50.0)*23.4 m/s = 0.642788 * 23.4 m/s = 15.04 m/s v = sin(50.0)*23.4 m/s = 0.766044 * 23.4 m/s = 17.93 m/s Now determine how many seconds it will take for the ball to get to the goal. t = 36.0 m / 15.04 m/s = 2.394 s The height the ball will be at time T is h = vT - 1/2 A T^2 where h = height of ball v = initial vertical velocity T = time A = acceleration due to gravity So plugging into the formula the known values h = vT - 1/2 A T^2 h = 17.93 m/s * 2.394 s - 1/2 9.8 m/s^2 (2.394 s)^2 h = 42.92 m - 4.9 m/s^2 * 5.731 s^2 h = 42.92 m - 28.0819 m h = 14.84 m Since 14.84 m is well above the crossbar's height of 3.05 m, the ball clears. It clears by 14.84 - 3.05 = 11.79 m</span>
4 0
3 years ago
which of the following describes water changing from liqyid to solid, please give me a proof for this question please i really n
Fittoniya [83]
The answers A, this is because Ice is originally water and when water goes below it's freezing point it turns into ice
4 0
3 years ago
Read 2 more answers
Other questions:
  • Which of these is a source of voltage?
    9·2 answers
  • A poodle racing across a lawn is an example of _____.
    7·1 answer
  • Two groups wanted to determine which size of parachute, when released, fell to the ground the slowest. Each group's design and r
    8·1 answer
  • At T = 0C and p = 1000mb, 1 g of dry air receives an amount of heat during an isochoric process. It is then observed that its p
    5·1 answer
  • Object that is relatively close to mirror ray diagrams for convex mirrors
    15·1 answer
  • Is a body which is moving in a negative direction but has a positive acceleration speeding up or slowing down?​
    11·1 answer
  • A 1380 kg car starts from rest at the
    13·1 answer
  • HELPP PLEEEAAAAASSSEEEEWKKKKKKK!!!!!
    13·2 answers
  • The tallest volcano on Mars
    7·2 answers
  • How much greater is the light-collecting area of a 6-meter telescope than a 3-meter telescope?.
    12·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!