Which of the following is an example of the Doppler effect? (2 points)
A. A water bug on the surface of a pond is producing small ripples in the water. The bug is not moving
B. A police car with its siren on is driving towards you, and you perceive the pitch of the siren to increase.
C. Scientists measure the speed of light and find that it is constant.
D. The gravitational pull of two objects on each other

Answers

Answer 1

Answer: B

Explanation:

Your'e asking about how waves get closer and louder A it isn't moving so no, C it's not saying if it's near or not and D is going trough another procedure so that leaves B behind


Related Questions

A 0.25-kilogram ball is observed to accelerate at 4,000 m/sec2 as it is hit with a bat.
How much force is exerted on the bat by the ball?

Answers

Answer:

1000 N

Explanation:

The force acting on an object given it's mass and acceleration can be found by using the formula

force = mass × acceleration

From the question we have

force = 0.25 × 4000

We have the final answer as

1000 N

Hope this helps you

Witch TWO types of rock are formed as particles get pushed closer together A. Intrusive igneous B. Extrusive igneous C. Sedimentary D. Metamorphosis

Answers

Answer:

C

Explanation:

Sedimentary rocks are the product of

1) weathering of preexisting rocks,

2) transport of the weathering products,

3) deposition of the material

4) compaction (two rocks pushed together)

5) cementation of the sediment to form a rock.

I WILL GIVE BRAINLIEST IF SOMEONE GETS THIS......

A eureka can of mass 100g and cross-section area 100cm2 is filled with water of density 1g/cm3. A piece of metal of mass 20g and density 8g/cm3 is lowered into the can. ( height of can 10cm ) calculate:
a) the total mass of can before the metal was lowered.
b) the volume of water that overflowed
c) the final mass of can and its content​

Answers

Answer:

Explanation:

a)

Firstly to calculate the total mass of the can before the metal was lowered we need to add the mass of the eureka can and the mass of the water in the can. We don't know the mass of the water but we can easily find if we know the volume of the can. In order to calculate the volume we would have to multiply the area of the cross section by the height. So we do the following.

100[tex]cm^{2}[/tex] x 10cm = 1000[tex]cm^{3}[/tex]

Now in order to find the mass that water has in this case we have to multiply the water's density by the volume, and so we get....

[tex]\frac{1g}{cm^{3} }[/tex] x 1000[tex]cm^{3}[/tex] = 1000g or 1kg

Knowing this, we now can calculate the total mass of the can before the metal was lowered, by adding the mass of the water to the mass of the can. So we get....

1000g + 100g = 1100g or 1.1kg

b)

The volume of the water that over flowed will be equal to the volume of the metal piece (since when we add the metal piece, the metal piece will force out the same volume of water as itself, to understand this more deeply you can read the about "Archimedes principle"). Knowing this we just have to calculate the volume of the metal piece an that will be the answer. So this time in order to find volume we will have to divide the total mass of the metal piece by its density. So we get....

20g ÷ [tex]\frac{8g}{cm^{3} }[/tex] = 2.5 [tex]cm^{3}[/tex]

c)

Now to find out the total mass of the can after the metal piece was lowered we would have to add the mass of the can itself, mass of the water inside the can, and the mass of the metal piece. We know the mass of the can, and the metal piece but we don't know the mass of the water because when we lowered the metal piece some of the water overflowed, and as a result the mass of the water changed. So now we just have to find the mass of the water in the can keeping in mind the fact that 2.5[tex]cm^{3}[/tex] overflowed. So now we the same process as in number a) just with a few adjustments.

[tex]\frac{1g}{cm^{3} }[/tex] x (1000[tex]cm^{3}[/tex] - 2.5[tex]cm^{3}[/tex]) = 997.5g

So now that we know the mass of the water in the can after we added the metal piece we can add all the three masses together (the mass of the can. the mass of the water, and the mass of the metal piece) and get the answer.

100g + 997.5g + 20g = 1117.5g or 1.1175kg

A jet aircraft is traveling at 214 m/s in hor-

izontal flight. The engine takes in air at a

rate of 115 kg/s and burns fuel at a rate of

2.53 kg/s. The exhaust gases are ejected at

276 m/s relative to the aircraft.

Find the thrust of the jet engine.

Answer in units of N.

Answers

Answer:

The thrust is  [tex]F = 7828.3 \  N [/tex]

Explanation:

From the question we are told that

   The speed of the jet aircraft is  [tex]v = 214 \ m/s[/tex]

    The rate at which the engine takes in air is [tex]\^ Q = 115 \ kg/s[/tex]

    The rate  at which the engine burns fuel is  [tex]\r m = 2.53 \ kg/s[/tex]

    The speed of the exhaust gases is  [tex]u = 276 \ m/s[/tex]

   

Generally the thrust of the engine is mathematically represented as

      [tex]F =[ \^ Q * ( u - v )] + (\r m * u)[/tex]

=>   [tex]F =[ 115 * ( 276  -  214 )]  + (2.53 * 276)[/tex]

=>   [tex]F = 7828.3 \  N [/tex]

A train travels at a speed of 30mph and travelled a distance of 240 miles. How long did it take the train to complete its journey? Must show your work​

Answers

Answer:

8

Explanation:

240 divided by 30 = 8

A boy is exerting a force of 70 N at a 50-degree angle on a lawnmower. He is accelerating at 1.8 m/s2. Round the answers to the nearest whole number.

What is the mass of the lawnmower?
What is the normal force exerted on the lawnmower?

Answers

The lawnmower accelerates in the positive horizontal direction, so that the net horizontal force is, by Newton's second law,

(70 N) cos(-50°) = m (1.8 m/s²)

where m is the mass of the lawnmower. Solve for m :

m = ((70 N) cos(-50°)) / (1.8 m/s²)

m ≈ 25 kg

The lawnmower presumably doesn't get lifted off the ground, so that the net vertical force is 0. If n is the magnitude of the normal force, then by Newton's second law,

n - m g + (70 N) sin(-50°) = 0

n = m g + (70 N) sin(50°)

n = (25 kg) (9.8 m/s²) + (70 N) sin(50°)

n ≈ 300 N

Which of the following is related to a person’s self-concept?
A) what neighborhood he or she lives in
B) his or her sense of self-worth
C) how good an athlete he or she is
D) how attractive he or she is

Answers

option D most likely

Answer:

Im not a 100 percent sure but i thinks it za A

Explanation:

HOW CAN AN APPLE DEMONSTRATE POTENTIAL AND ENERGY

Answers

Answer and Explanation in one:

In physics, potential energy is the energy held by an object because of its position relative to other objects, stresses within itself, its electric charge, or other factors. So basically, you could possibly demonstrate with a variety of examples. One example may be just sitting on a table, waiting to get rolled off. I know it sounds silly, so here's another example. You are holding a bow and arrow, you pull back the arrow, aiming at the target. You are holding the arrow, filling it with potential energy. When it is let go, it is kinetic energy, the act of an object in motion, slowly riding of it's potential energy.

Which point has the most Potential energy? [Select]
Which point has the most Kinetic energy? [ Select ] ​

Answers

Answer:

Most potential energy: A

Most kinetic energy: D

Explanation:

Kinetic Energy is the type of energy an object has due to its state of motion. It's proportional to the square of the speed.

The equation for the kinetic energy is:

[tex]\displaystyle K=\frac{1}{2}mv^2[/tex]

Where:

m = mass of the object

v = speed at which the object moves

The gravitational potential energy is the energy stored in an object because of its height h in a gravitational field.

It can be calculated with the equation:

U=m.g.h

The point where the object has the most potential energy is that where it has more height. It corresponds to point A.

When the object is at zero height, all of its potential energy was transformed to kinetic, thus the point where the kinetic energy is D.

Most potential energy: A

Most kinetic energy: D

Answer:

potentail enegry at point a and kinetic enegy at point c

Explanation:

i did this i fourth grade please mark brainlist

Near the surface of Earth, what is the acceleration of an object due to the force of gravity? !!!!! Please answer !!!!!

Answers

Answer:

Weight. Recall that the acceleration of a free-falling object near Earth's surface is approximately g=9.80m/s2 g = 9.80 m/s 2 . The force causing this acceleration is called the weight of the object, and from Newton's second law, it has the value mg.

Explanation:

The weight of an object is measured in air to be 7.0 N. The
object is then immersed in water and its apparent weight is
measured to be 4.0 N. Determine the buoyant force and state
whether or not the object floats.​

Answers

Answer:

Buoyant force = 3.0 N

The object will not float.

Explanation:

Apparent weight of a body immersed in water is the actual weight of object minus buoyant force

Given in the question that;

Weight of object in air = 7.0 N

Apparent weight of object = 4.0 N

4.0 N = 7.0 N - Buoyant force

Buoyant force = 7.0 - 4.0 = 3.0 N

In this case, the buoyant force is less than weight of the object thus the object will sink.

In which of the following situations would there be initial energy in the system?

An apple sits motionless on the ground near a tree

A spring is compressed and held at compression by a person before releasing it

A bowstring is neither pulled nor stretched on a bow

An object rests at a velocity of 0 on a flat surface at ground level

Answers

Answer:

A spring is compressed and held at compression by a person before releasing it

Explanation:

All the other answers are showing things that are at rest and have no energy starting nor going through them. This answer show how the energy is starting and being released.

What average net force is required to stop a 1950 kg car in 10.5 s if it’s initially traveling at 28m/s

Answers

Answer:

An average net force of 5200 N is needed to stop the car

Explanation:

Cinematics and Dynamics

Cinematics describes the variables involved in the movement without dealing with its causes. There are four main concepts in cinematics: Velocity (or its scalar equivalent, the speed), acceleration, time, and displacement (or the scalar equivalent, distance).

The acceleration can be calculated by:

[tex]\displaystyle a=\frac{v_f-v_o}{t}[/tex]

The initial speed is vo=28 m/s, it stops (vf=0) in t=10.5 seconds, thus the acceleration is:

[tex]\displaystyle a=\frac{0-28}{10.5}[/tex]

[tex]a = -2.67~m/s^2[/tex]

The acceleration is negative because the car loses speed.

Knowing the mass of the car m=1950 Kg, we can calculate the net force required to stop the car by using the formula:

F = m.a =1950*2.67

F = 5200 N

An average net force of 5200 N is needed to stop the car

A 3900 kg truck is moving at 6.0 m/s what is the kinetic energy

Answers

Answer:

70200J

Explanation:

k.E = 1/2mv^2

K.E = 1/2(3900)(6)^2

Here you go, hope this helped

What type of energy is stored in a pendulum at the top of its arc?

Answers

Answer:

potential

Explanation:At this point the energy is stored in a form called potential energy. This means that the system has the potential to do work or to become active thanks here to the weight's position high above the lowest point of its swing.

I was gonna say that so in case you have doubts (person who uploaded question) your good to go

a toy car is wound up and released on the floor. it accelerates at a rate of 0.4 m/s/s . the mass of the care is 3kg. what is the force that the cars wheels exert on the floor.

Answers

Answer:

1.2N

Explanation:

f=m×a

m=3kg

a=.4m/s/s

3×.4=1.2

kg×m/s/s = N

What types of energy is used to make a lamp work

Answers

Answer:

Electrical energy

Explanation:

Earthquakes
Shaking of the ground
Seismographs
Scientific method

Answers

Answer:

C. seismographs

Explanation:

Theirs another name for seismographs but c is correct

4) Choose Yes or No next to the descriptions to indicate whether or not an object
is accelerating,
A car slows down,
A car stays the same speed,
A car goes faster,
Luke walks at a constant speed of 4 mph,
Luke walks north at a constant speed of 4 mph,
Luke walks north at a constant speed of 4 mph, turns right, and walks
Type here to search

Answers

1. No
2. No
3.yes
4.no
5.no
6.yes

Plant and Snail Gizmo

Answers

What? Cool okay lol haha
Chose the plant to be the best answe chosen more than a plant

A 0.85-kg arrow flies through the air at a speed of 19 m/s. What is the momentum of the arrow?
16 kg m/s
22 kg m/s
160 kg m/s
360 kg m/s

Answers

Answer:

16 kg m/s

Explanation:

The momentum of an object can be found by using the formula

momentum = mass × velocity

From the question we have

momentum = 0.85 × 19 = 16.15

We have the final answer as

16 kg m/s

Hope this helps you

according to newtons third law of motion what happened to the back of a skateboard when the person pushes down on the front of the skateboard

Answers

Answer:I think it would start moving

Explanation:

How much power is used if a force of 35 newtons is used to push a box a distance of 10 meters in 5 seconds?w=350j

Answers

The answer your looking for is 70watts

Answer:

How much power is used if 350J of work is done when pushing a box for 5 seconds.

Explanation:

the answer is 70watts

Making and disposing of synthetic materials affects the amount of natural resources that are available. It also can harm the environment. These problems may not affect us in our lifetime. Who will these problems affect?

Answers

Answer:

What I put- This will affect animals, the earth, and could affect future generations. Plastic also gets into the oceans causing sea creaters die by eating it.

Sample Answer- Problems that arise from the unavailability of natural resources and from environmental hazards will affect the generations that follow us.

Explanation:

Answer:

This will affect animals, the earth, and could affect future generations. Plastic also gets into the oceans causing sea creaters die by eating it.

Explanation:

Two ice-skaters are skating in circles on a frozen pond. Maria is making large circles with a radius of 12 m and skating 4.5 m/s. Her friend, Samantha, is making smaller circles with a radius of 6 m but is not skating as quickly, going only 3.8 m/s.

How could each skater increase her centripetal acceleration without changing the size of her path? Explain your reasoning.

Answers

Answer: Samantha has the largest centripetal acceleration of 2.4 m/s^2. Maria has only 1.69 m/s^2.

Explanation:

A 615.00 kg race car is uniformly traveling around a circular race track. It takes the race car 20.00 seconds to do one lap around the 80.00 m radius circular track. What is the frequency of the race car's circular motion?

Answers

Answer:

The value is  [tex]f = 0.05 \ Hz[/tex]

Explanation:

From the question we are told that

     The mass of the car is  [tex]m = 615 \ kg[/tex]

      The period of the circular motion is  [tex]T = 20 \ s[/tex]

      The radius  is [tex]r = 80 \ m/s[/tex]

Generally the frequency of the circular motion is  

       [tex]f = \frac{1}{T }[/tex]

=>    [tex]f = \frac{1}{ 20 }[/tex]

=>    [tex]f = 0.05 \ Hz[/tex]

I WILL GIVE BRAINLYIST
Which of the following types of stars had the smallest initial mass? (10 points)

Group of answer choices

Blue main sequence

Neutron star

Red supergiant

White dwarf

Answers

Answer:

White dwarf

Explanation:

3. If I run 150m in 30 seconds, what speed will I have been running at?

Answers

Answer:

speed = distance/time

Explanation:

speed = 150/30

speed =5m/s

you were running fast .....5m/s is a good speed

The temp of the metal in a running car engine is 388 K. Find this temp in Celsius.

Answers

Answer:

115°c

Explanation:

°c=k-273

388-273=115

What 2 factors affect the impulse on an object in a collision?

Answers

force an friction?

i looked it up an thats all i can find
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