PHYSICS COLLEGE

Hearing the siren of an approaching fire truck, you pull over to side of the road and stop. As the truck approaches, you hear a tone of 460 Hz; as the truck recedes, you hear a tone of 410 Hz. How much time will it take to jet from your position to the fire 5.00 km away, assuming it maintains a constant speed?

Answers

Answer 1

Answer:

Answer:

The truck will reach there in 250 seconds.

Explanation:

The frequency due to doppler effect, when the observer is stationary and the source is moving towards it is

$f_(obv)$ = $(v)/(v-v_(s) ) f$

where v= velocity of sound in air

$v_(s)$ = velocity of source of sound

f= frequency of sound and

$f_(obv)$ = frequency oberved due to Doppler effect

$(v)/(v-v_(0) ) f$ = 460------------------------------------------( 1 )

The frequency due to doppler effect, when the observer is stationary and the source is moving away from it

$f_(obv)$ = $(v)/(v+v_(s) ) f$

where v= velocity of sound in air

$v_(s)$ = velocity of source of sound

f= frequency of sound and

$f_(obv)$ = frequency oberved due to Doppler effect

$(v)/(v+v_(0) ) f$ = 410-------------------------------------------( 2 )

Dividing ( 1 ) by ( 2 )

$(v+v_(s) )/(v-v_(s) ) =(460)/(410)$

$(v+v_(s) )/(v-v_(s) ) =(46)/(41)$

41v + 41 $v_(s)$ = 46v - 46 $v_(s)$

87 $v_(s)$ = 5v

$v_(s)$ = $(5)/(87)v$

Velocity of Sound (v)= 348 m/s

$v_(s)$ =20 m/s

Therefore, the truck is moving at 20 m/s.

$Time=(Distance)/(Time)$

Distance= 5000 m

Time= $(5000)/(20)$

Time= 250 s

Time = 4 min 10 sec

They would draw a total of 21.25 amperes

Explanation:

The total power consumed is

1200 W+ 750 W + 600 W= 2550 Watts

The formula relating the power consumed, the voltage and the current is given as

$P=IV$ ---------------1

given that the voltage supply is 120V

$2550=I*120\n\I=(2550)/(120) \n\nI= 21.25amps$

A research Van de Graaff generator has a 2.00-m diameter metal sphere with a charge of 5.00 mC on it. (a) What is the potential near its surface?
(b) At what distance from its center is the potential 1.00 MV?
(c) An oxygen atom with three missing electrons is released near the Van de Graaff generator. What is its energy in MeV when the atom is at the distance found in part b?

Answers

Answer:

a) $V=49.5MV$

b) $r=49.5m$

c) $\Delta U=3*(49.5-1)=145.5 MeV$

Explanation:

a) The potential equation is given by:

$V=k(Q)/(r)$

k is the electrostatic constant ( $k=9.9*10^(9)Nm^(2)/C^(2)$ )

Q is the charge Q = 5mC

r is the radius of the sphere r = 1 m

$V=9.9*10^(9)(5*10^(-3))/(1)=49.5MV$

b) We solve it using the same equation.

Here we need to find r:

$r=k(Q)/(V)$

$r=9.9*10^(9)(5*10^(-3))/(1*10^(6))$

$r=49.5m$

c) The relation between difference potential and electrical energy is:

$\Delta U=\Delta Vq$

here q is 3e becuase oxygen atom has three missing electrons

Therefore:

$\Delta U=3*(49.5-1)=145.5 MeV$

I hope it heps you!

Experts in model airplanes develop a supersonic plane to scale, it moves horizontally in the air while it is conducting a flight test. The development team defines that the space that the airplane travels as a function of time is given by the function: e (t) = 9t 2 - 6t + 3 Determine what acceleration the scale airplane has (Second derivative).

Answers

Explanation:

e(t) = 9t² − 6t + 3

The velocity is the first derivative:

e'(t) = 18t − 6

The acceleration is the second derivative:

e"(t) = 18

why does the value of capacitance of a capacitor increases in parallel combination but not in series??

Answers

It is easiest to consider problems like this by thinking exclusively about parallel plate capacitors for which $C \equiv (Q)/(V) =\kappa \epsilon_0 (A)/(d)$ where Q is the charge separated (+Q on one plate, -Q on the other), V is the voltage difference between the plates, A is the area of each plate, and d is the separation between the plates.

When capacitors are connected in parallel, the voltage across each capacitor is the same. But with two capacitors, it will require more charge to reach the voltage V than it would with just one capacitor. In fact, if capacitor 1 requires charge

Which of the following is not a motivation behind taking performance enhancing drugs?A.Having bigger, stronger muscles B.improving recovery time fir injuries C. Pumping

Answers

Answer:

C. Pumping

Explanation:

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Answer: Losing weight due to decreased appetite

Explanation: because you guys trust me

A speed skater moving across frictionless ice at 8.8 m/s hits a 6.0 m -wide patch of rough ice. She slows steadily, then continues on at 5.8 m/s . What is her acceleration on the rough ice?

Answers

A speed skater moving across frictionless ice at 8.8 m/s hits a 6.0 m -wide patch of rough ice. Her acceleration on the rough ice is -3.65 m/s².

v² - u² = 2 a ∆x, where u and v are initial and final velocities, respectively; a is acceleration.

and ∆x is the distance traveled (because the skater moves in only one direction).

Thus, (5.8 m/s)² - (8.8 m/s)² = 2 a (6.0 m)

a = ((5.8 m/s)² - (8.8 m/s)²) / (12 m)

a = -3.65 m/s².

Thus, A speed skater moving across frictionless ice at 8.8 m/s hits a 6.0 m -wide patch of rough ice. Her acceleration on the rough ice is -3.65 m/s².

Learn more about Acceleration, refer to the link:

brainly.com/question/2303856

#SPJ3

Recall that

v² - u² = 2 a ∆x

where u and v are initial and final velocities, respectively; a is acceleration; and ∆x is the distance traveled (because the skater moves in only one direction).

So we have

(5.8 m/s)² - (8.8 m/s)² = 2 a (6.0 m)

a = ((5.8 m/s)² - (8.8 m/s)²) / (12 m)

a = -3.65 m/s²

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