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
lisabon 2012 [21]
3 years ago
10

A radar gun can determine the speed of a moving automobile by measuring the difference in frequency between emitted and reflecte

d radar waves. What process is used in determining the speed of the car?
Question 7 options:

resonance


refraction


diffraction


doppler effect
Physics
1 answer:
kupik [55]3 years ago
4 0

Answer:

Doppler effect.

Explanation:

The velocity of the moving car affects the wavelengths of the reflecting  radio waves according to the principle of Doppler effect. Therefore, for a car moving away from the radar gun, the wavelength of the radio waves is increased, and for a car moving towards the gun, the wavelength is decreased. The degree of increase or decreases depends on the speed of the car, so if you know how much a wavelength has changed, you know the velocity of the car.

You might be interested in
Please help. Basic. Brainliest will be given.
kkurt [141]

Answer:

28.7 m at 46.9°

Explanation:

The x component of the displacement is:

x = 6 m cos 0° + 25 m cos 57°

x = 19.6 m

The y component of the displacement is:

y = 6 m sin 0° + 25 m sin 57°

y = 21.0 m

The total displacement is found with Pythagorean theorem:

d = √(x² + y²)

d = 28.7 m

And the direction is found with trig:

θ = tan⁻¹(y/x)

θ = 46.9°

6 0
3 years ago
Read 2 more answers
In April 1974, Steve Prefontaine completed a 10.0 km race in a time of 27 min , 43.6 s . Suppose "Pre" was at the 7.43 km mark a
Novay_Z [31]

Answer:

Acceleration, a = 0.101 m/s²

Explanation:

Average speed = total distance / total time.

At the 7.43km mark, total distance = 7.43km or 7430m

Total time = 25 * 60 s = 1500s

Average speed = 7430m/1500s = 4.95m/s

He then covers (10 - 7.43)km = 2.57 km = 2570 m

in t = 27m43.6s - 25min = 2m43.6s = 163.6 s

Then he accelerates for 60 s, and maintains this velocity V, for the remaining (163.6 - 60)s = 103.6 s.

From V = u + at; V = 4.95m/s + a *60s

Distance covered while accelerating is

s = ut + ½at² = 4.95m/s * 60s + ½ a *(60s)² = 297m + a*1800s²

Distance covered while at constant velocity, v after accelerating is

D = velocity * time

Where v = 4.95m/s + a*60s

D = (4.95m/s + a*60s) * 103.6s = 512.82m + a*6216s²

Total distance covered after initial 7.43 km, S + D = 2570 m, so

2570 m = 297m + a*1800s² + 512.82m + a*6216s²

2570 = 809.82 + a*8016

a = 809.82m / 8016s² = 0.101 m/s²

8 0
3 years ago
An open organ pipe is 2.46 m long, and the speed of the air in the pipe is 345 m/s.
lukranit [14]

Answer:

Fundamental frequency is 70.12 m

Explanation:

For an open organ pipe, the fundamental frequency is given by :

f=\dfrac{nv}{2l}

n = 1 for fundamental frequency

v is speed of sound in air, v = 345 m/s

l is length of open organ pipe, l = 2.46 m

Substituting values in above formula. So,

f=\dfrac{1\times 345}{2\times 2.46}\\\\f=70.12\ Hz

So, the fundamental frequency of this pipe is 70.12 m.

6 0
3 years ago
An object exhibits SHM with an angular frequency w = 4.0 s-1 and is released from its maximum displacement of A = 0.50 m at t =
vivado [14]

Explanation:

It is given that,

Angular frequency, \omega=4\ s^{-1}

Maximum displacement, A = 0.5 m at t = 0 s

We need to find the time at which it reaches its maximum speed. Firstly, we will find the maximum velocity of the object that is exhibiting SHM.

v_{max}=A\times \omega

v_{max}=0.5\times 4

v_{max}=2\ m/s............(1)

Acceleration of the object, a=\omega^2A

a=4^2\times 0.5

a=8\ m/s^2...............(2)

Using first equation of motion we can calculate the time taken to reach maximum speed.

v=u+at

t=\dfrac{v-u}{a}

t=\dfrac{2-0}{8}

t = 0.25 s

So, the object will take 0.25 seconds to reach its maximum speed. Hence, this is the required solution.

4 0
3 years ago
A. What are the three longest wavelengths for standing waves on a 240-cm-long string that is fixed at both ends?
vovangra [49]

Answer:

a) the three longest wavelengths = 4.8m, 2.4m, 1.6m

b) what is the frequency of the third-longest wavelength = 75Hz

Explanation:

The steps and appropriate formula and substitution is as shown in the attached file.

5 0
3 years ago
Other questions:
  • Consider a very low (zero) friction, 5.0 kg skateboard on a ramp at an angle of 15 degrees to the horizontal. What would be the
    12·1 answer
  • A 30.0-kgkg box is being pulled across a carpeted floor by a horizontal force of 230 NN , against a friction force of 210 NN . W
    5·1 answer
  • How many atoms of oxygen are in the product for the double replacement reaction?
    15·1 answer
  • At a given point on a horizontal streamline in flowing air, the static pressure is â2.0 psi (i.e., a vacuum) and the velocity is
    8·1 answer
  • Our solar system formed from a huge cloud of dust and gas called a _____.
    7·2 answers
  • Purse-seine fishing is known to be the safest fishing method for protecting dolphins.
    9·2 answers
  • THIS ONE IS URGENT!!!
    12·1 answer
  • The scientific study of the process and phenomena of aging is
    5·1 answer
  • What do you call rocxs that form under intense heat and pressure
    14·1 answer
  • Rudy plans to conduct an experiment using three rosebushes of the same variety and size. His hypothesis is that the plant
    5·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!