help me solve the following question below in the attachment

Answer:

false

Explanation:

because no machines have 100% efficient

Answer:

1.Wave frequency is the number of waves that pass a fixed point in a given amount of time. The SI unit for wave frequency is the hertz (Hz), where 1 hertz equals 1 wave passing a fixed point in 1 second. A higher-frequency wave has more energy than a lower-frequency wave with the same amplitude.

Answer:

10,920 meters

Explanation:

distance = speed × time

which is, d = 21 × 520

Answer:

10920

Explanation:

distance traveled= 21 (speed) ×520 (time)

=10920

Answer:

2.67 ohm

Explanation:

V=IR

R=V/I

In which V is voltage and I is current and R is resistance

Answer:

the answer to this question is option c

there process which eventually takes place is called refraction

Explanation:

please do consider as brainlest if useful

Answer:

The answer is 581

Explanation:

I just took the Quick Check and got it right.

Answer:

Explanation:

You can decompose those vectors into their components in x and y direction. For the first vector:

[tex]\vec{r}_{1}=r_{1}\cos 30\hat{i}+r_{1}\sin 30\hat{j}=3.14(\frac{1}{2}\sqrt{3}\hat{i}+\frac{1}{2}\hat{j})=1.57\sqrt{3}\hat{i}+1.57\hat{j}[/tex]

For the second vector:

[tex]\vec{r}_{2}=r_{2}\cos 60\hat{i}-r_{2}\sin60 \hat{j}=1.355\hat{i}-1.355\sqrt{3}\hat{j}[/tex]

The sum of two vectors will be:

[tex]\vec{r}=\vec{r}_{1}+\vec{r}_{2}=(1.57\sqrt{3}+1.355)\hat{i}+(1.57-1.355\sqrt{3})\hat{j}\approx 4.0711\hat{i}-0.77415\hat{j}[/tex]

The magnitude of the sum of two vectors is:

[tex]r=\sqrt{(4.0711)^{2}+(-0.77415)^{2}}\approx 4.14[/tex] meter

Answer:

4.14m

Explanation:

Answer:

true

Explanation:

Friction helps your vehicle stop quickly. this statement ids true. Hence option A us correct. A vehicle can stop more rapidly because to friction. The brake pads rub on the turning braking discs or drums when the brakes are applied.

The friction slows the moving vehicle down and eventually causes it to halt by converting its kinetic energy into heat energy.  The effectiveness of the braking action will increase with the level of friction between the brake parts. For rapid stops, friction between the tyre and the road is also important.

The vehicle's forward motion is opposed by friction created by the tyres' gripping action on the road surface, which helps in stopping and decelerating. Rapid vehicle stopping would be incredibly difficult and risky without friction.

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Hi there!

We can use Ampère's Law:

[tex]\oint B \cdot dl = \mu_0 i_{encl}[/tex]

B = Magnetic field strength (B)
dl = differential length element (m)
μ₀ = Permeability of free space (T/Am)

Since this is a closed-loop integral, we must integrate over a closed loop. We can integrate over a rectangular-enclosed area of the rim of the solenoid - ABCD - where AD and BC are perpendicular to the solenoid.

Thus, the magnetic field is equivalent to:
[tex]\oint B \cdot dl = \int\limits^A_B {B} \, dl + \int\limits^B_C {B} \, dl + \int\limits^C_D {B} \, dl + \int\limits^D_A {B} \, dl[/tex]

Since AD and BC are perpendicular, and since:
[tex]\oint B \cdot dl = B \cdot L = BLcos\phi[/tex]

[tex]BLcos(90) = 0[/tex]

If perpendicular to the field, the equation equals 0.

Additionally, since AB is outside of the solenoid, there is no magnetic field present, so B = 0. The only integral we integrate now is:
[tex]\oint B \cdot dl = \int\limits^C_D {B} \, dl[/tex]

Which is horizontal and inside the solenoid. Let the distance between C and D be 'L', and the enclosed current is equivalent to the number of loops multiplied by the current:

[tex]B L = \mu_0 Ni[/tex]

N = # of loops per length multiplied by the length, so:
[tex]BL = \mu_0 nL i \\\\B = \mu_0ni[/tex]

Plug in the given values and solve. Remember to convert # of loops to # of loops per unit length.

[tex]B = \mu_0 (100/0.1)(2) = (4\pi *10^{-7})(1000)(2) = \boxed{0.00251 T}[/tex]

Answer:

When fuels burn in combustion reactions, they release useful thermal energy (heat). Combustion reactions are used to heat our homes, power most cars, and to generate a lot of our electricity.

Energy production from the reaction is what drives life and human greed. We stay alive by eating carbon-rich compounds, which are then burned in a spectacularly controlled and efficient manner to provide us with energy. It is the all-important energy term in the combustion equation that has made life on Earth possible

Answer: It's 2 and 3

Explanation:

Answer:

algebraic sum of moments of all the forces acting on the body about the axis of rotation is zero, the body is in equilibrium. According to the principle of moments, in equilibrium: Sum of anticlockwise Moments = Sum of clockwise moments.

Condition:

For an object to be in equilibrium, it must be experiencing no acceleration.

Hope it may helpful to you

Answer:

A) X-rays

Explanation:

Airport security screenings use X-rays because they can penetrate through bags to see objects that are located within that are obscured through normal view.

X- rays are used to  test  body in airports. Low energy waves are used to screen baggages and human body. Thus option A is correct.

Electromagnetic spectrum is the arrangement of radiations in the order of decreasing wavelength or increasing energy and frequency. The order is radio waves, microwaves, infrared, visible, ultraviolet, x-rays and gamma rays.

x -rays are highly energetic short waves which can be easily penetrate through a body. X-ray is used in different diagnostic techniques. X-rays easily penetrate through  tissues and provide the scanned images of internal parts.

In airport security screening x-rays are used to screen baggages and human bodies. High energetic waves are causing serious health risks. Hence, lower energy x-rays are used in testing.

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it has no energy because its being held still

it has motion energy because it will fall if let go

Explanation:

no. of seconds in a year = 60 × 60 × 24 × 365

= 31,536,000 seconds

so 2.05 × 10⁵ into years = 0.0065 years (approximately)

Answer:

When the speed is changing is the correct answer

Explanation:

Because acceleration is rate of change of velocity

PLEASE MARK ME BRAINLIEST IF MY ANSWER IS CORRECT PLEASE

Since the frequency of sound in a medium is constant, therefore, the concert-goers would hear the low notes and high notes at the same time.

A dispersive medium is a medium which spreads out or disperses a substance passing through it.

Since CO2 is a dispersive medium, it means sound waves passing through it would be dispersed based on wavelength.

The note of a sound depends on its frequency, the higher the frequency, the higher the note.

Frequency of sound is constant, therefore, the concert-goers would hear the low notes and high notes at the same time.

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Answer:

the moon will be in between the sun and the moon covering the earth view of the sun

Answer:

We dont have a understandable Ansewer for this

Explanation:

Given that the magnitude of the forces is greater towards the left; the ball slows down as it moves to the right because the horizontal forces are unbalanced.

We have to know that force is a vector quanty. The direction in which the ball will move is  dependent on the direction and magnitude of the resultant force.

Now considering the statements, the pairs of  statements that are true are;

description: the ball slows down as it moves to the right because the horizontal forces are unbalanced, with the larger force acting to the left.

explanation: The ball speeds up as it moves downward because the vertical forces are unbalanced, with the larger force acting downward.

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If an object changes the speed of direction, its velocity also changes. Any change in velocity results in acceleration.

Hope that helps!

Answer:

The "new" moon phase is being shown because the moon shown is directly between the sun and earth and is not visible from the earth because of the brightess of the sun.

The total mechanical energy is kinetic energy + potential energy, so we can look at the object's potential energy to determine the place where it has maximum and minimum kinetic energy.

Potential energy is determined by the equation PE = mgh, where the height is the only changing variable here. Therefore, we look at the height to answer these questions.

Which point on the graph would have the most kinetic energy?

Which point on the graph would have the least kinetic energy?

What point on the graph would have just a little less potential energy than point E?

What point on the graph would have just a little more potential energy than point F?

What point on the graph would have just a little less potential energy than point G?

For a DJ is setting up their equipment and measures the sound level near a speaker to be 55.65dB, the new sound level is mathematically given as

L=50.470dB

Generally, the equation for the sound level  is mathematically given as

l=10logl/io

Therefore

logl/io=5.57

Hence

I=3.715*10^−8

In conclusion

L'=10log(3*3.715*10^−8)/10^{-12}

L=50.470dB

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During the phase change in which heat is being added but the temperature remains constant, the heat energy is used to break the bonds in the molecules.

A phase change is the conversion of one state of matter to another. e.g. solid to liquid or liquid to gas.

Substances can exists in three states namely;

In a change of phase, heat energy is needed to break the existing bonds between the molecules of the initial state. For example, heat energy is needed to break the bonds of ice to form water.

However, during this phase change, the temperature remains constant.

Therefore, during the phase change in which heat is being added but the temperature remains constant, the heat energy is used to break the bonds in the molecules.

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Explanation:

13x - 26 + 39 = 0

13x=26-39

13x=-13

x= -1

[tex]13x-26+39=0\\\\\implies 13x +13 = 0\\\\\implies 13x = -13\\\\\implies x = -\dfrac{13}{13}\\\\\implies x = -1[/tex]