All categories

2 years ago

I need some help w/ this:

Physics

1 answer:

pochemuha2 years ago

5 0

Answer:

The velocity of the police car is, v = 17.798 m/s

Explanation:

Given data,

The actual frequency of the siren, f = 2010 Hz

The observed frequency of siren is, f' = 2120 Hz

The velocity of the observer, v' = 0 m/s

The velocity of the source, v = ?

The formula for Doppler effect,

$f'=\frac{(V+v')}{(V-v)}f$

Where,

V - velocity of sound waves in air.

$v=V-(V+v')\frac{f}{f'}$

Substituting the given values,

$v=343-(343+0)\frac{2010}{2120}$

v = 17.798 m/s

Hence, the velocity of the police car is, v = 17.798 m/s

You might be interested in

A student falls off a cliff into the lake 54.0 m below. What is the final velocity of the student?

Vladimir79 [104]

Answer:

$v_{y}$ = -32.53 m / s

this velocity is directed downwards

Explanation:

This is a free fall exercise, let's use the expression

$v_{y}^{2}$ = v_{oy}^{2} + 2 g (y -yo)

where we are assuming that there is friction with the air, as the body falls its initial velocity is zero

v_{oy} = √ 2g (y - y₀)

let's calculate

v_{y} = √ (2 9.8 (0-54.0))

$v_{y}$ = -32.53 m / s

this velocity is directed downwards

6 0

3 years ago

As you know, the oceans cover most of the earth, and contain a huge amount of resources. Protecting these resources is one reaso

matrenka [14]

A is the answer your looking for

8 0

3 years ago

Read 2 more answers

Can someone answer this please.?? I really need help

svetlana [45]

Answer:

1. is the age group 35 and 44

2. is 2006 i think its 2006 i cant really tell in the picture but its the one before the last one!

6 0

2 years ago

"Giant Swing", the seat is connected to two cables as shown in the figure (Figure 1) , one of which is horizontal. The seat swin

Bingel [31]

The horizontal force is m*v²/Lh, where m is the total mass. The vertical force is the total weight (233 + 840)N.

Fx = [(233 + 840)/g]*v²/7.5 

v = 32.3*2*π*7.5/60 m/s = 25.37 m/s 

The horizontal component of force from the cables is Th + Ti*sin40º and the vertical component of force from the cable is Ta*cos40º 

Thh horizontal and vertical forces must balance each other. First the vertical components: 

233 + 840 = Ti*cos40º 

solve for Ti. (This is the answer to the part b) 

Horizontally 

[(233 + 840)/g]*v²/7.5 = Th + Ti*sin40º 

Solve for Th 

Th = [(233 + 840)/g]*v²/7.5 - Ti*sin40º 

using v and Ti computed above.

3 0

2 years ago

The particles that make up protons and neutrons are called

Sphinxa [80]

Answer:

Quark

Explanation:

In the past the proton,neutron and electron were believed to be indivisible. Quarks were later discovered to be particles that make up the proton and neutron. Quarks are known as fast moving points of energy and are usually joined to one another through gluons. Neutron has two down quarks and one up quark while proton has two up quarks and one down quark.

6 0

3 years ago