can someone help me please

Answer:

B. electromagnetic waves

Answer:

I known this much much except c and d. Hope this helps, thank you !!

Answer:

Yes,

Explanation:

Yes, Amanda is eligible for a tax deduction. Because of her medical expense. Her medical expense is $6,500 and it exceeds 7.5% of her adjusted gross income which is $60,000.

7.5% of $60,000 = 7.5/100 * 60000

7.5% of $60,000 = $4,500.

If 7.5% is $4,500, and her medical expenses is $6,500, then she's eligible for a tax deduction

Answer:

I think C.

Explanation:

I'm not sure

Answer:

it would decrease i think

Explanation:

Answer:

HMMMMMM??????

Explanation:

Answer:

c

Explanation:

plz make me brainliest i have answered

Answer:

Force = 485000 Newton.

Explanation:

Given the following data;

Mass = 485000 kg

Initial velocity = 20m/s

Final velocity = 25m/s

Time, t = 5 seconds

To find the force;

First of all, we would calculate the acceleration of the train i.e the rate of change of the velocity of the train with respect to time.

Mathematically, acceleration is given by the equation;

[tex]Acceleration (a) = \frac{final \; velocity - initial \; velocity}{time}[/tex]

[tex]a = \frac{v - u}{t}[/tex]

Where;

a is acceleration measured in [tex]ms^{-2}[/tex]

v and u is final and initial velocity respectively, measured in [tex]ms^{-1}[/tex]

t is time measured in seconds.

Substituting into the equation, we have;

Acceleration = (25 - 20)/5

Acceleration = 5/5

Acceleration = 1m/s²

Force is given by the multiplication of mass and acceleration.

Mathematically, Force is;

Force = mass * acceleration

Force = 485000 * 1

Force = 485000 Newton.

Answer:

The book remained in its state of rest before the car started to move forward as no direct force acted on it.

Explanation:

According to Newton's first law of motion, a body will continue in its present state of rest, or if it is in motion, will continue to move with uniform speed in a straight line unless aced upon by an external force. This tendency of a body to remain in its state of reset or uniform motion in a straight line is known as inertia and is directly proportional to the mass of the body. The more massive a body, the more inertia it possesses. Thus Newton's first law is also known as the law of inertia.

Considering the case of the book on the dashboard of a stationary car which suddenly starts to move. While the car is stopped at the traffic light, the dashboard where the book sits and the book are both at rest. When the car begins to move forward, the dashboard moves forward with it. However as the book is not a part of the car, no force is directly acting on it, so the book so it stays at rest due to its inertia.

Therefore, as the car is moving forward, the stationary book appears to move backward from the reference point of the car, sliding off the dashboard.

Answer:

a) ρ = 2.33 10⁵ C / m³, b) INSULATING

Explanation:

a) For this exercise we use the important concept of density

            ρ = Q / V

The volume of a sphere is

           V = 4/3 πr3

            V = 4/3 π (1.27 10⁻²)³

            V = 8.58 10⁻⁶ m³

let's calculate

           ρ = 2 / 8.58 10⁻⁶

           ρ = 2.33 10⁵ C / m³

b) in a conductor the charges are mobile, therefore due to electoral repulsion all the charges must concentrate on the surface.

In an insulator the charges are fixed, therefore they are distributed throughout the volume

Consequently the sphere must be INSULATING

Answer:

543.04 m

Explanation:

The 2 charges are:

q1 = q2 = 5 C

Distance apart is r

Force; F = 762149 N

We will use the formula from coulumbs law;

F = kq1•q2/r²

Where k is coulumbs constant = 8.99 × 10^(9) N.m²/C²

Making r the subject, we have:

r = √((8.99 × 10^(9) × 5 × 5)/762149)

r ≈ 543.04 m

Answer:

a) The frequency of the third harmonic is 786 Hz

b) The frequency of the first harmonic is 340 Hz

c) The frequency of the fifth harmonic is 1640 Hz

Explanation:

The rule is as follows:

If the first harmonic frequency (also called the fundamental frequency) is F, then:

The frequency of the second harmonic (also called the second overtone) is:

2*F

The frequency of the third harmonic (also called the third overtone) is:

3*F

And so on.

With this information, we can answer the questions:

a) We want to find the frequency of the third harmonic, such that the frequency of the first harmonic is 262 Hz.

Then we have F = 262Hz

And the frequency of the third harmonic will be:

3*F = 3*262Hz = 786 Hz

b) First harmonic for a string whose fifth harmonic frequency is 1700Hz.

Let's define F as the first frequency (the one we want to find)

Then the fifth harmonic frequency can be written as:

5*F = 1700Hz

With this equation we can find the value of F:

F = 1700Hz/5 = 340Hz

c) We want to find the fifth harmonic for a string whose third overtone (this is the same as the third harmonic) frequency is 984 Hz.

Then if the frequency of the first harmonic is F, we know that:

3*F = 984 Hz

With this we can find the value of F:

F = 984 Hz/3 =328 Hz

Now that we know the frequency of the first harmonic, we can find the frequency of the fifth harmonic:

5*F = 5*328 Hz = 1640 Hz

Answer:

The magnitude of the boat's velocity is 8.21 km/h.

Explanation:

We can find the boat's velocity as follows:

[tex] \Epsilon V_{x} = V_{w_{x}} + V_{b_{y}} [/tex]            

[tex] \Epsilon V_{y} = V_{w_{y}} + V_{b_{y}} [/tex]

Where:

[tex]V_{w_{x}}[/tex] and [tex]V_{w_{y}}[/tex] are the components of the velocity of the water in the x and y-direction

[tex]V_{b_{x}}[/tex] and [tex]V_{b_{y}}[/tex] are the components of the velocity of the boat in the x and y-direction

Since the angle is 15° we have:

[tex] \Epsilon V_{x} = -4.0 km/h*sin(15) + 0 = -1.04 km/h [/tex]  

[tex] \Epsilon V_{y} = 4.0 km/h*cos(15) - 12.0 km/h = -8.14 km/h [/tex]

Now, the velocity of the boat is:  

[tex] V = \sqrt{V_{x}^{2} + V_{y}^{2}} = \sqrt{(-1.04 km/h)^{2} + (-8.14 km/h)^{2}} = 8.21 km/h [/tex]

Therefore, the magnitude of the boat's velocity is 8.21 km/h.

I hope it helps you!

Answer:

Mechanical Waves

Explanation:Sound waves in air are longitudinal waves because particles of the medium through which the sound is transported vibrate parallel to the direction that the sound wave moves. A vibrating string can create longitudinal waves.

Answer:

Mechanical Wave

Explanation:

Sound is an example of a Mechanical Wave.

Answer:

The force that pulls the car down is Wₓ = 14052.6 N and the one that pushes the car up is F = 26552.6 N

Explanation:

For this exercise we will use Newton's second law, let's set a reference system where the x axis is parallel to the plane, in the adjoint we can see the forces in the system.

           sin  35 = Wₓ / W

            cos 35 = W_y / W

            Wₓ = W sin 35

            W_y = W cos 35

            Wₓ = 2500 9.8 sin 35

             Wₓ = 14052.6 N

let's write the equations for each axis

and

Y axis  

       N-W_y = 0

       N = W_y

X axis  

       F -Wₓ = m a

       F = Wₓ + m a = mg sin 35 + m a

       F = m (a + g sin 35)

let's calculate

       F = 2500 (5 + 9.8 sin 35)

       F = 26552.6 N

The force that pulls the car down is Wₓ = 14052.6 N and the one that pushes the car up is F = 26552.6 N

Answer:

Every electric circuit, regardless of where it is or how large or small it is, has four basic parts: an energy source (AC or DC), a conductor (wire), an electrical load (device), and at least one controller (switch). Visualize what happens when you switch on a room light.

Answer:

Kinetic energy = 5400000 J

Height, h = 45.91 m

Explanation:

It is given that,

Mass of the roller coaster train, m = 12,000 kg

Velocity of the train, v = 30 m/s

Kinetic energy is given by :

KE=\dfrac{1}{2}mv^2KE=

2

1

mv

2

KE=\dfrac{1}{2}\times 12000\ kg\times (30\ m/s)^2KE=

2

1

×12000 kg×(30 m/s)

2

KE=5400000\ JKE=5400000 J

So, the kinetic energy of the train at the top speed is 5400000 J.

For height

According to law of conservation of energy :

PEni+KE i=PE f+KE fPE i +KEi

=PEf +KE f

0+5400000\ J=mgh+00+5400000 J=mgh+0

5400000\ J=mgh5400000 J=mgh

h is the height.

5400000\ J=12000\ kg\times 9.8\ m/s^2\times h5400000 J=12000 kg×9.8 m/s

2

×h

h=45.91\ mh=45.91 m

Hence, this is the required solution.

Answer: Choice A, that X and Y are both positive

Explanation: positive charges are attracted to negative charges, so for their electric fields, positive charges point outward while negative charges point inward. In this model, it shows that both X and Y are pointing outward, hence they both have to have positive charges

Answer:

State vector.

Explanation:

To determine exactly where a satellite is located, engineers must think and calculate positions in three dimensions. A set of data telling engineers all of the various elements of position, velocity, and time for a satellite or spacecraft is known as a state vector.

This ultimately implies that, state vectors gives a detailed description of the position and velocity of a satellite at a specific period of time. Also, the more accurate your input state vector, the more accurate would be the position, velocity and time for a satellite when trying to determine its location. Therefore, the time tag of a state vector shouldn't be too far from the present time of the day.

Answer:

Scientists can discuss and compare very large numbers, which is useful because substances in everyday quantities contain very large numbers of atoms and molecules.

Explanation:

Answer:

23.6 m

Explanation:

We are given that

Mass of ball, m=7.0 kg

Force, F=810 N

Distance, s=2.0 m

We have to find the height of ball from the point where it releases.

Work done=K.E

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

[tex]v^2=\frac{2Fs}{m}[/tex]

Substitute the value

[tex]v^2=\frac{2\times 810\times 2}{7}[/tex]

[tex]v^2=\frac{3240}{7}[/tex]

K.E=P.E

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

[tex]\frac{1}{2}v^2=gh[/tex]

Where g=[tex]9.8m/s^2[/tex]

[tex]\frac{1}{2}\times \frac{3240}{7}=9.8h[/tex]

[tex]h=\frac{3240}{7\times 2\times 9.8}[/tex]

[tex]h=23.6 m[/tex]

Answer:

a)  E = 1.06 10⁻¹⁹ J,     b)   v = 9.78 10⁵ m / s

Explanation:

The physical magnitudes can be given in several units, but in general all must be reduced to the same system in a given exercise, the most used system is the international (SI)

           1 eV =q V=  1.6 10⁻¹⁹ J

let's reduce the quantities requested

a) E = 1.0 eV to Joule

           E = 1.0 eV (1.6 10⁻¹⁹ J / 1 eV)

           E = 1.06 10⁻¹⁹ J

b) the kinetic energy is given by

           K = ½ m v²

           v = [tex]\sqrt{\frac{2K}{m} }[/tex]

the mass of the proton is

          m = 1,673 10⁻²⁷ kg

let's reduce the energy to the SI system

           E = 5000 ev (1.6 10-19 J / 1 eV) = 8000 10⁻¹⁹ J

let's calculate

           v = [tex]\sqrt{ \frac{2 \ 8000 \ 10^{-19}}{1.673 \ 10^{-27} } }[/tex]

           v = [tex]\sqrt{ 95.637 \ 10^{10} }[/tex]

           v = 9.78 10⁵ m / s

Answer:

Magnitude = 55

Quantity = Speed

Explanation:

We are told that the speed is 55 mph. This implies that the magnitude is 55 while the unit is mph.

Also, physical quantities are usually things that can be measured such as distance, voltage, temperature e.t.c

Answer:

i think its speed

Explanation:

Answer:

They must have the same units when expressed in base units

Explanation:

Too add any two values together you need them to be in the same units. but You can convert diffrent units of the same messure to each other in order to achive this; ie you can add meeters to feet if you multiply the meters by 3.28 but you can't add mass and length together.

With the concept of  pattern we find that the answer for the sum of physical magnitudes is:

They must have the same units when expressed in base units.

To add two phsical quantities to meet some requirements:

* Must be of the same type

* Must be in the same base units

That they have the same type implies that we cannot add length with time or masses, length or speeds must be added with their pairs

The use of the same base unit guarantees that we use the same pattern, or that we must reduce the magnitudes to the same pattern, for example: we cannot add meters with inches directly, we must reduce inches to meters, which is the unit of the international system.

International System  it guarantees the existence of common and reproducible patterns for all physical quantities.

Add two phsical quantities, the correct answer is:

must have the same units in base units

In conclusion, the measurement system and units allows adding magnitude of the same type with the same units of a base unit or standard.

learn more about measured here:  https://brainly.com/question/20732638

Answer:

1. Wind Energy turns blades of wind turbine 

2. Rotation of the rotor in the generator 

3. Energy moves from the generator into power lines 

4. Energy moves through power lines 

5. Energy from power lines causes the toaster to glow red 

Explanation:

 im sorry if im late

Answer:

First) is b

Second) is true

Third) is C (not sure tho)

Explanation:

Because of their longer wavelengths, AM waves reflect off a layer of the upper atmosphere called the ionosphere.

Answer:

3.5kgm/s

Explanation:

We can calculate the momentum of Julieta

momentum = m(v-u)

Momentum = 0.2(20-2.5)

Momentum = 0.2(17.5)

Momentum = 3.5

Hence the momentum of Julieta is 3.5kgm/s

Answer:

9.33333333 m / s2

Explanation:

140 N divided by 15 kg