In which of the following situations is the Doppler effect absent?

Answer:

The correct answer is b: 96 m.

Explanation:

The total distance in the horizontal direction traveled by Danger Dog can be calculated using the following equation:

[tex] x_{f} = x_{0} + v_{0_{x}}t + \frac{1}{2}at^{2} [/tex]   (1)

Where:

[tex] x_{f}[/tex]: is the final position in the horizontal direction =?                                      

[tex]x_{0}[/tex]: is the initial position in the horizontal direction = 0                                      

[tex] v_{0_{x}} [/tex]: is the initial velocity in the horizontal direction = 32 m/s

t: is the time

a: is the acceleration = 0 (he is accelerated only by gravity)

So, we need to find the time. We can find it as follows:

[tex] y_{f} = y_{0} + v_{0_{y}}t - \frac{1}{2}gt^{2} [/tex]    (2)

Where:

[tex] y_{f}[/tex]: is the final position in the vertical direction = 0                                      

[tex]y_{0}[/tex]: is the initial position in the vertical direction = 45 m                                      

[tex] v_{0_{y}} [/tex]: is the initial velocity in the vertical direction = 0

g: is the acceleration due to gravity = 10 m/s²      

By solving equation (2) for "t" we have:

[tex] t = \sqrt{\frac{2(y_{0} - y_{f})}{g}} = \sqrt{\frac{2*45 m}{10 m/s^{2}}} = 3 s [/tex]

Hence, the total distance traveled by Danger Dog in the x-direction is (equation 1):

[tex] x_{f} = 32 m/s*3 s = 96 m [/tex]    

Therefore, the correct answer is b: 96 m.

I hope it helps you!

Answer: The height of rollercoaster cart above the ground is 1.53 m.

The velocity of rollercoaster cart is 5.29 m/s.

Explanation:

Potential energy is the energy occupied by a substance due to its position. Formula for potential energy is as follows.

P.E = mgh

where,

m = mass of substance

g = gravitational constant = [tex]9.8 m/s^{2}[/tex]

h = height

Substitute the values into above formula as follows.

[tex]P.E = m \times g \times h\\67500 J = 4500 kg \times 9.8 m/s^{2} \times h\\h = \frac{67500 J}{4500 kg \times 9.8 m/s^{2}}\\= 1.53 m[/tex]

Hence, the height of rollercoaster cart above the ground is 1.53 m.

Kinetic energy is the energy occupied by the motion of a substance. Formula for kinetic energy is as follows.

[tex]K.E = \frac{1}{2}m \times v^{2}[/tex]

where,

m = mass of substance

v = velocity of substance

Substitute the values into above formula as follows.

[tex]K.E = \frac{1}{2}m \times v^{2}\\63000 J = \frac{1}{2} \times 4500 kg \times v^{2}\\v^{2} = \frac{63000 J \times 2}{4500 kg}\\v = 5.29 m/s[/tex]

Hence, the velocity of rollercoaster cart is 5.29 m/s.

Answer:

i'm sorry i'm not a physics student

Answer:

Mass (m) = 5.4 kg

Force (f) = 20 N

Acceleration (a) = ?

Acceleration= m × a

[tex]m \times a \\ = 5.4 \times 20 \\ = 108 \: ms ^{ - 2} [/tex]

=> The resulting acceleration of the object is 108 m/s².

Answer:

The remaining lights would shine with the same brightness.

Explanation:

Answer:

Explanation:

I included proof that A is the right answer. Hope this helps!

Answer:

C

Explanation:

C

20*9.8*0.5

98

Answer:

The Earth spins on its axis once a day.

Explanation:

In simple words,The Earth revolves on its axis once every 24 hours and circles the sun once every 365 days. The Earth's rotation on its axis, not its orbit throughout the sun causes day as well as night. The word 'one day' refers to the period it requires the Earth to spin entirely on its axis, which involves both day as well as night.

Answer:

t = 125 seconds

Explanation:

Given that,

The mass of a train, m = 50,000 kg

Initial speed, u = 5 m/s

Stopping force, F = 2000 N

We know that,

Force, F = ma

Where

a is acceleration

[tex]F=\dfrac{m(v-u)}{t}\\\\t=\dfrac{m(v-u)}{F}\\\\t=\dfrac{50000(0-5)}{-2000}\\\\t=125\ s[/tex]

So, it will take 125 seconds to stop the car.

Answer:

A. A motor

Explanation:

Answer:

A sound wave is called a longitudinal wave because compressions and rarefactions in the air produce it. The air particles vibrate parallel to the direction of propagation.

Explanation:

Kinetic energy of an object is given by :

[tex]E=\dfrac{1}{2}mv^2[/tex]

Where

m is mass and v is velocity of the object

A. Mass, m = 300 kg.

Speed, v = 60 km/h = 16.67 m/s

[tex]E=\dfrac{1}{2}\times 300\times 16.67^2\\\\=41683.33\ J[/tex]

B. Mass, m = 1100 kg.

Speed, v = 60 km/h = 16.67 m/s

[tex]E=\dfrac{1}{2}\times 1100\times 16.67^2\\\\=152838.89\ J[/tex]

C. Mass, m = 900 kg.

Speed, v = 80 km/h = 22.22 m/s

[tex]E=\dfrac{1}{2}\times 900\times 22.22^2\\\\=222177.78\ J[/tex]

D. Mass, m = 2000 kg.

Speed, v = 50 km/h = 13.88 m/s

[tex]E=\dfrac{1}{2}\times 2000\times 13.88^2\\\\=192654.4\ J[/tex]

The kinetic energy in case C is maximum.

Answer:

Explanation:

By Kirchoff's laws, I1 + I2 = 3

I2 = 3 - I1

Following circuit on the left, V = summation of IRs

9 = I1*3 + 3*2

3*I1 = 9 - 6 = 3

I1 = 1A

I2 = 3 -1 = 2A

Following circuit on the right, V = summation of IRs

ε = I2*4.5 + 3*2

= 2*4.5 + 6

= 15V

Answer:

a = 12.2 m/s²

Explanation:

Given: 5 kg, 61N

To find: Acceleration (a)

Solution:

A = F ÷ m

= 61 ÷  5  

= 12.2 m/s²

Newtons are derived units, equal to 1 kg-m/s². In other words, a single Newton is equal to the force needed to accelerate one kilogram one meter per second squared.

Automation:

1. The creation and application of technology to monitor and control the production and delivery of products and services.

2. The use of machines and technology to make processes run on their own without manpower.

Examples to make you understand better:

Automations are in Meetings, Hiring Process, Employee Analytics.

Quote:

"In manufacturing, a system or method in which many or all of the processes of production, movement, and inspection of parts and materials are automatically performed or controlled by self-operating machinery, electronic devices, etc."

Fulcrum:

Picture Included.

1. The support about which a lever turns

2.The support or point of support on which a lever turns in raising or moving something

Consumerism:

Quote:

"Consumerism has a good and bad side. Although consumerism drives economic growth and boosts innovation, it comes with a fair share of problems ranging from environmental and moral degradation to higher debt levels and mental health problems."

Definition:

1. "The growth of consumerism has led to many organizations improving their service to the customer"

2. Spending money and consuming goods is good for the economy.

3. The protection or promotion of the interests of consumers.

I hope this helped!+*♡

Answer:

6.67 ohm

Explanation:

From the question given above, the following data were obtained:

Resistor 1 (R₁) =20 ohm

Resistor 2 (R₂) = 20 ohm

Resistor 3 (R₃) = 20 ohm

Equivalent Resistance (R) =?

Since the resistors are arranged in parallel connection, the equivalent resistance can be obtained as follow:

1/R = 1/R₁ + 1/R₂ + 1/R₃

1/R = 1/20 + 1/20 + 1/20

1/R = (1 + 1 + 1) / 20

1/R = 3/20

Invert

R = 20/3

R = 6.67 ohm

Therefore, the equivalent resistance is 6.67 ohm.

Answer:

88.2 J (I put 10kg instead of 3kg last time oops)

Explanation:

https://www.calculatorsoup.com/calculators/physics/gravitational-potential.php

Answer:

[tex]\boxed {\boxed {\sf 88.2 \ Joules}}[/tex]

Explanation:

Potential energy is energy due to position. It is the product of the object's mass, height, and the gravitational acceleration.

[tex]E_p= m \times \ g \times h[/tex]

The mass of the ball is 3 kilograms and the height is 3 meters. Assuming this is on Earth, the gravitational acceleration is 9.8 meters per square second.

Substitute these values into the formula.

[tex]E_p= 3 \ kg \times 9.8 \ m/s^2 \times 3 \ m[/tex]

Multiply the first two numbers.

[tex]E_p=29.4 \ kg*m/s^2 \times 3 \ m[/tex]

Multiply again.

[tex]E_p= 88.2 \ kg*m^2/s^2[/tex]

[tex]E_p= 88.2 \ J[/tex]

The ball has 88.2 Joules of potential energy.

Answer:

Una rueda de 20 cm de radio gira de modo que en dos minutos ... Datos: • Radio 20 cm = 0,2 m • Tiempo = 2 min 30 s= 150 s • N° de vueltas ... m • f = 300 rpm = 5 Hz • Período • T = 1 f = 1 5 = 0,2 s • Rapidez angular ... 160 rpm (frecuencia de la rueda 2) • 10 * 160 = 80 * y donde y = 20 rpm

Explanation:

Answer:

Conditions under which the belt and pulleys are operating – The friction between the belt and pulley may decrease substantially if the belt happens to be muddy or wet, as it may act as a lubricant between the surfaces.

Explanation:

I hope that this would be helpful

Answer:

C I think but I'm not sure

Explanation:

Because by adding mass it would add more gravitational pull

Answer:

The action of erosion alone can change the earth's surface. Erosion can wash away nutrients on the earth's surface, change the appearance of the soil of a particular area over time, can bore holes, that form caves, change landscapes for example when the earth is hit with gully erosion by continuous water runoff over time. Erosion can move soil to a new area.

Explanation:

Weathering involves breaking down rock into smaller pieces without any form of formal movement of those broken rock pieces. These processes that can lead to weathering are caused by mechanical, chemical, and organic processes which can happen over time. Erosion can now move broken rock pieces or soil to another place by water or wind. Weathering and erosion constantly change the Earth's surface.

Answer:

64 ohms =R

Explanation:

R is directly proportional to V

R is inversely proportional to I(Current

Answer:

If I'm not wrong; I think the answer is A

Explanation:

A. Increasing kinetic energy

Answer:

Explanation:

It can cause  damage to the blood vessels.  It Can cause  heart failure, vision loss, stroke, kidney disease, and other health problems.

Hope this helps!!!

Answer:

Carl Linnaeus discovered Classification

Answer:

Carl Linnaeus

Explanation:

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