Direct current is produced by<br> an electric motor<br> an armature<br> a solenoid<br> a battery

An emergency vehicle blowing its siren is moving

Georgia [21]

The frequency produced by the siren is 631.12 Hz

<h3>Doppler effect</h3>

The variation in frequency when a source of sound moves relative to an observer is determined by the doppler effect.

<h3>Frequency of observer</h3>

So, the frequency of the observer f' = (v ± v')f/(v ± v") where

f' = 590 Hz

f = frequency of source or siren ,

v = speed of sound = 330 m/s,

v' = speed of observer = 0 m/s (since you are stationary) and

v" = speed of source = 23 m/s

Since the source moves away from the detector, the sign in the denominator is positive and v' = 0 m/s

So, f' = (v + 0)f/(v + v")

f' = vf/(v + v")

Since, we require the frequency of the source, make f subject of the formula, we have

<h3>Frequency of siren</h3>

f = (v + v")f'/v

Substituting the values of the variables into the equation, we have

f = (v + v")f'/v

f' = (330 m/s + 23 m/s) × 590 Hz/330 m/s

f' = 353 m/s × 590 Hz/330 m/s

f' = 208270 m/sHz/330 m/s

f' = 631.12 Hz

The frequency produced by the siren is 631.12 Hz

Learn more about doppler effect here:

brainly.com/question/2169203

5 0

3 years ago

As the distance between 2 objects increases, what happens to gravitational force?

ExtremeBDS [4]

Answer:

the force decreases

Explanation:

Gravitational force is depending on it's mass and the distance between two object

The attachment shows us to understand relationship of it's

F ∝ 1/ (r)2

there for gravitational force is inversely proportional to it's distance . when distance between two object is increased, Then force will be decreased

3 0

3 years ago

The dogs of four-time Iditarod Trail Sled Dog Race champion Jeff King pull two 100-kg sleds that are connected by a rope. The sl

azamat

Answer:

Part a)

$a = 2.4 m/s^2$

Part b)

$F = 120 N$

Explanation:

Two sleds are connected by a rope

mass of each sled is given as

$m = 100 kg$

now we know that dog exert pulling force on the rope connected to first sled

$F = 240 N$

Part a)

By newton's first law we know that

$F = (m + m)a$

$240 = (100 + 100)a$

$a = \frac{240}{100}$

$a = 2.4 m/s^2$

Part b)

As we know that force between two ropes will pull the sled behind

so we will have

$F = ma$

$F = 100(1.20)$

$F = 120 N$

7 0

3 years ago

Read 2 more answers

An electrostatic paint sprayer has a 0.17 m-diameter metal sphere at a potential of 25.0 kV that repels charged paint droplets o

Troyanec [42]

Answer:

$q=0.236uC$

Explanation:

From the question we are told that:

Diameter $d=0.17m$

Radius $r=0.17/2=>0.085$

Potential $E=25.0kV$

Generally the equation for Potential on spere is mathematically given by

$E=\frac{1}{4 \pi e_0}*\frac{q}{r}$

Therefore

$q=\frac{25*10^3*0.085}{\frac{1}{4 \pi e_0}}$

Where

$\frac{1}{4 \pi e_0}=9*10^9$

Therefore

$q=\frac{25*10^3*0.085}{(9*10^9}}$

$q=0.236uC$

4 0

3 years ago

What is the maximum wavelength of incident light that can produce photoelectrons from silver? The work function for silver is Φ=

zalisa [80]

Answer:

4.24nm

0.385eV

Explanation:

Maximum wavelength (λmax) :

λmax = ( hc) /Φ

h = plancks constant = 6.63 * 10^-34

c = speed of light = 3*10^8

1ev = 1.6 * 10^-19

Φ = 2.93eV = 2.93* (1.6*10^-19) = 4.688*10^-19

λmax = [(6.63 * 10^-34) * (3 * 10^8)] / 4.688*10^-19

λmax = 19.89 * 10^-26 / 4.688*10^-19

λmax = 4.242 * 10^-7 m

λmax= 4.24nm

B.)

E = hc / eλ eV

λ = 3.75nm = 3.75 * 10^-7m = 375 *10^-9

E = (6.63 * 10^-34) * (3 * 10^8) / (1.6 * 10^-19) * (375 * 10^-9)

E = 19.89 * 10^-26 / 600 * 10^-28

E = 0.03315 * 10^-26 + 28

E = 0.03315 * 10^2

E = 3.315 eV

Stopping potential : (3.315 eV - 2.93eV) = 0.385eV

7 0

3 years ago

Direct current is produced by an electric motor an armature a solenoid a battery