To hear a train approaching from far away, why is it more convenient to put the ear to the track?

Answer:

b.false i think

Explanation:

i hope i am correct and helps you

Answer:false

Explanation:

I just did it

Answer: tendons connect muscles to bones

Explanation:

Answer:

Pmax = 67.5 KN

Explanation:

We need to calculate the maximum allowable value of P for both aluminum and steel bars.

FOR STEEL BARS:

Since,

(σallow)st = (Pmax)st/A

where,

(σallow)st = maximum allowable stress of steel bar = 200 MPa = 2 x 10⁸ Pa

A = Cross-sectional area of steel bar = 450 mm² = 0.45 x 10⁻³ m²

(Pmax)st = Maximum allowable force for steel bar = ?

Therefore,

2 x 10⁸ Pa = (Pmax)st/0.45 x 10⁻³ m²

(Pmax)st = (2 x 10⁸ Pa)(0.45 x 10⁻³ m²)

(Pmax)st = 9 x 10⁴ N = 90 KN

FOR Aluminum BARS:

Since,

(σallow)al = (Pmax)al/A

where,

(σallow)al = maximum allowable stress of Al bar = 150 MPa = 1.5 x 10⁸ Pa

A = Cross-sectional area of Aluminum bar = 450 mm² = 0.45 x 10⁻³ m²

(Pmax)al = Maximum allowable force for Aluminum bar = ?

Therefore,

1.5 x 10⁸ Pa = (Pmax)al/0.45 x 10⁻³ m²

(Pmax)al = (1.5 x 10⁸ Pa)(0.45 x 10⁻³ m²)

(Pmax)al = 6.75 x 10⁴ N = 67.5 KN

Since,

(Pmax)al < (Pmax)st

Therefore,

The maximum allowable force will be:

Pmax = (Pmax)al

Pmax = 67.5 KN

Answer:

The strong force binds quarks together in clusters to make more-familiar subatomic particles, such as protons and neutrons. It also holds together the atomic nucleus and underlies interactions between all particles containing quarks

Explanation:

PLEASE GIVE ME BRAINLIEST IF NEW IT SHOULD SAY MARK AS BRAINLIEST IF NOT YOULL HAVE TO WAIT A DAY AND BRAINLY WILL REMIND YOU

Answer:

54 W

Explanation:

Power = Voltage* Current =V*I = 120V*0.45A =54 Watt

Answer:

0.45 miles

Explanation:

since, car will be running on the edge of track, distance covered in one lap by car will be equal to circumference of track.\

we will use value of pi as 22/7

Circumference for any circular shape is given by [tex]\piD[/tex][tex]\pi D[/tex]

Hence, in one lap [tex]\pi D[/tex] distance will be covered

in 7 laps [tex]7 \pi D[/tex] distance will be covered.

but is given that 7 laps should be equal to 10 miles

so 10 miles will be equal to [tex]7\pi D[/tex]

[tex]7\pi D= 10 \ miles\\=> 7*(22/7)* D= 10 \ miles\\=> 22D = 10 \ miles\\=> D = 10/22 \ miles\\=> D = 0.45 \ miles[/tex]

Thus, diameter of track will be 0.45 miles to meet the requirement.

Answer:

T1 = T2 = 602.33 N

Explanation:

I attached an image of the forces diagram below.

The x component of the forces for this cases is:

[tex]\Sigma F_x=T_1cos\theta-T_2cos\theta=0\\\\T_1cos\theta=T_2cos\theta\\\\T_1=T_2[/tex]

And the y components:

[tex]\Sigma F_y=T_1sin\theta+T_2sin\theta-W=0\\\\T_1=T_2=T\\\\\Sigma F_y=2Tsin\theta=W\\\\T=\frac{W}{2sin\theta}[/tex]

The angle is calculated by using the information about the length of the cable and the vertical distance of the traffic light:

[tex]\theta=tan^{-1}(\frac{1}{15})=3.81\°[/tex]

Thus, you obtain:

[tex]T=\frac{80N}{2(sin3.81\°)}=601.33N[/tex]

hence, the tension in both segments of the cable is 602.33 N

Answer:

Explanation:

The question in english is:

A ray of light falls under an angle of incidence of 30 degrees on a flat surface that separates two transparent materials with indexes of refractions 1.60 and 1.40, respectively.

Calculate the angle of refraction (from the environment with the lower index of refraction)

Solution

According to Snell's Law :

[tex]n_{1}sin(\theta_{1})=n_{2}sin(\theta_{2})[/tex]

Where:

[tex]n_{1}=1.6[/tex]  is the first medium index of refraction

[tex]n_{2}=1.4[/tex]  is the second medium index of refraction

[tex]\theta_{1}=30\°[/tex]  is the angle of the incident ray

[tex]\theta_{2}[/tex] is the angle of the refracted ray

We need to find [tex]\theta_{2}[/tex] from the equation above,

[tex]\theta_{2}=sin^{-1}(\frac{n_{1}}{n_{2}}sin\theta_{1} )[/tex]

[tex]\theta_{2}=sin^{-1}(\frac{1.6}{1.4}sin(30\°)[/tex]

[tex]\theta_{2}=34.84\°[/tex]

Answer:

there is an option for uploading the pic of a diagram while posing any question on brainly. hope you use that feature of the app to upload graph of your question so that it can be well answered

Answer: It’s A!

Explanation: I took the test

Answer:

In mathematics, the difference of two squares is a squared (multiplied by itself) number subtracted from another squared number. Every difference of squares may be factored according to the identity. in elementary algebra.

Explanation:

Answer:

T = 2.82 seconds.

The frequency [tex]\mathbf{f = 0.36 \ Hz}[/tex]

Amplitude A = 25.5 cm

The maximum speed of the glider is [tex]\mathbf{v = 56.87 \ rad/s}[/tex]

Explanation:

Given that:

the time taken for 11 oscillations is 31 seconds ;

SO, the time taken for one oscillation is :

[tex]T = \frac{31}{11}[/tex]

T = 2.82 seconds.

The formula for calculating frequency can be expressed as :

[tex]f = \frac{1}{T}[/tex]

[tex]f = \frac{1}{2.82}[/tex]

[tex]\mathbf{f = 0.36 \ Hz}[/tex]

The amplitude is determined by using the formula:

[tex]A = \frac{d}{2}[/tex]

The limits that the spring makes the oscillations are from 10 cm to 61 cm.

The distance of the glider is, d = (61 - 10 )cm = 51 cm

Replacing 51 for d in the above equation

[tex]A = \frac{51}{2}[/tex]

A = 25.5 cm

The maximum speed of the glider is:

[tex]v = A \omega[/tex]

where ;

[tex]\omega = \frac{2 \pi}{T}[/tex]

[tex]\omega = \frac{2 \pi}{2.82}[/tex]

[tex]\omega = 2.23 \ rad/s[/tex]

[tex]v = A \omega[/tex]

[tex]v = 25.5 *2.23[/tex]

[tex]\mathbf{v = 56.87 \ rad/s}[/tex]

Explanation:

hope this helps you...........

The magnetic flux through the loop when the plane of the loop is perpendicular to the magnetic field is 0.0256 Weber.

The magnetic field is the region of space where a charged object experiences magnetic force when it is moving.

The formula for magnetic flux is given as;

φ = BAcosθ

Given, a rectangular loop of wire that can rotate about an axis through its center is placed between the poles of a magnet in a magnetic field with a strength of 0.40 T. The length of the loop L is 0.16 m and its width w is 0.040 m.

Area of the loop = L x w

                        A  = 0.16 x 0.040 m

                         A = 0.0064 m²

So, flux will be

φ = 0.4 x  0.0064 x cos90°

φ = 0.00256 Wb

Thus, magnetic flux through the loop when the plane of the loop is perpendicular to the magnetic field is 0.0256 Weber.

Learn more about magnetic field.

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Answer:

Matter in the universe is made up of atoms, particles if electrons were to be stationary, they would have fallen into the nucleus because of electrostatic force acting on them destroying very existence of an atom we know.

Answer: 250 watts

Explanation:

energy=250J

Time=1 sec

Power=energy ➗ time

Power=250 ➗ 1

Power=250

Power is 250 watts

According to the question,

Energy,

Time,

The formula,

→ [tex]Power =\frac{Energy}{Time}[/tex]

By substituting the values, we get

              [tex]= \frac{250}{1}[/tex]

              [tex]= 250 \ Watts[/tex]

Thus the above approach is right.

Learn more about power here:

https://brainly.com/question/23443372

Answer:

v = 30 /1500= 0.02 m/s

................

Answer:

c

Explanation:

not sure i think heating beach

Answer:

I think it might be A: Alec but tell me if I'm wrong

Explanation:

Answer:

a

Explanation:

i did it on e d g e n u i t y

Given :- A resistor of 150 ohm, hence Resistance (R) = 150 ohm

Potential Difference (v) = 24 V

Current (I) = ?

V = IR

24 = I × 150

I = 24/150

I = 0.16 ampere

hope it helps!

Answer:

water vapor is a type of gas

Explanation:

all gas are in air state of form

hope this helps

Answer:

chemical potential energy

Explanation:

When the sun's radiant energy falls on Earth's oceans, it causes water to change state by evaporating. The form of energy water vapor have is chemical potential energy. when heat energy of sun falls on water surface, its state change from liquid to gas. This gas rises above in the form of water vapor. Its a chemical change. If this vapor get condense/ cool, it will turn into liquid again. We can say that vapor has potential to transform into water again. Thus, the energy stored in water vapor is called chemical potential energy.

Answer:

Explanation:

The Sun emits waves called "Solar Waves", which have a wavelengths between 160 and 400 nanometers. According to the electromagnetic spectrum, these waves are defined as Ultraviolet, which have a frequency around the order of [tex]10^{16}[/tex], which is really intense and high energy.

Therefore, the answer is Ultraviolet Waves.

Answer:

1,211.1 kg.

Explanation:

the force of gravity is less on the moon than on earth, so if the man can lift 200kg on earth, he could lift a greater amount on the moon because there is less resistance from gravity.

To know the amount of mass he can lift on the moon, we first need to know the amount of weight that is equivalent to those 200kg here on earth. This because the weight of the object is equal to the force that must be applied to lift it, and that force is applied by the man and it will be the same here and on the moon.

We calculate weight using the formula:

[tex]w=mg[/tex]

where [tex]w[/tex] is the weight of the object (the force with which the earth attracts the object) [tex]m[/tex] is the mass and g the acceleration of gravity.

so

[tex]w=200g[/tex]

for earth the acceleration due to gravity is:  [tex]g=9.81m/s^2[/tex]

thus:

[tex]w=(200kg)(9.81m/s^2)\\w=1962N[/tex]

now we use this value to calculate the mass he can lift on the moon, since for the moon [tex]g=1.62m/s^2[/tex].

we use the same equation, w =mg substituting w = 1962N and [tex]g=1.62m/s^2[/tex]:

[tex]w=mg\\\\1962N=m(1.62m/s^2)\\\\m=\frac{1962N}{1.62m/s^2}\\\\ m=1,211.1kg[/tex]

he can lift 1,211.1 kg.

You can also find the result using the approximate value of the acceleration of gravity on the moon as g/6, where g is the acceleration on earth.

Answer:

electrostatic attraction

Explanation:

Atoms form chemical bonds with other atoms when there's an electrostatic attraction between them. This attraction results from the properties and characteristics of the atoms' outermost electrons, which are known as valence electrons.

Explanation:

The expression for the magnetic field around the current carrying wire is given by :

[tex]B=\dfrac{\mu_o I}{2\pi r}[/tex]

Here,

I is electric current and r is distance from the wire.

The factors affect the strength of magnetic field around current carrying wire are :

Answer:

B) Distance and Time

Explanation:

Equation for speed: S = D / T

Speed equals the distance you traveled divided by the amount of time it took to get to that destination.

The two factors which are required to determine the speed of a object are distance traveled by it and time taken by it.

The speed is the rate at which the total distance by a object is traveled in the time taken.

Speed of a object can be given as,

[tex]s=\dfrac{d}{t}[/tex]

Here, (d) is the distance traveled by the object and (t) is time taken but the object to cover that distance.

As the unit of the distance is measured in the meter and the time measure in the second. Thus the speed of a object is measured in the meter per second.

In the vehicles the speed of vehicle is also measured in the kilometre per hour or miles per hour.

Hence, the two factors which are required to determine the speed of a object are distance traveled by it and time taken by it.

Thus the option B is the correct option.

Learn more about the speed here;

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Answer:

A transformer that increases the voltage from primary to secondary (more secondary winding turns than primary winding turns) is called a step-up transformer. Conversely, a transformer designed to do just the opposite is called a step-down transformer.

Explanation:

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Answer:

the stones are released from rest at the same time, the stone that is on Earth to have more acceleration must first reach the ground

Explanation:

For this exercise we will use the law of universal attraction on each planet and Newton's second law to calculate the body's acceleration on each planet

          F = ma

          F = G m M / r²

Where G is the universal gravitational constant, m the mass of the body, M the mass of the planet and r the distance

Let's start with the Earth

       G m M / r² = m a

        a = G M / r²

let's look for the distance

    r = [tex]R_{e}[/tex] + h

    a = G M / (R_{e} + h)² = (G M /R_{e}²)  1 /(1 + h /R_{e})² ²

as h << R_{e} we can expand this function

    (1 + h /R_{e})⁻² = 1 -2 h / Re + ...

with h /R_{e} it is very small we can despise it

        a = G M /R_{e}

the amount in parentheses is called the acceleration due to gravity

     g = G M / R_{e}²

     g = 6.67 10⁻¹¹ 5.98 10²⁴ / (6.37 10⁶)²

     g = 9.8 m / s ²

Now let's calculate the acceleration on Mars, let's use index 2 for this planet

     a = G M2 / R_{2}²

     a = 6.67 10⁻¹¹ 6.42 10²³ / (3.37 10⁶)

     a = 3.77 m / s²

Let's analyze these results as the stones are released from rest at the same time, the stone that is on Earth to have more acceleration must first reach the ground

 we can use the equation

           y = v₀ t - ½ to t2

           v₀ = 0

           t = √ (2y / a)

we see that as the acceleration is greater the time decreases

Answer:

Nuclear fusion is the process in which two atomic nuclei are fused together into a larger single nucleus, releasing energy in the process. ... In proton-proton fusion, four hydrogen atoms are fused into a single helium-4 atom, releasing a lot of energy in the process.

Explanation:

Answer:Because it likes to repel and attract opposites