which statement about force is incorrect

Answer:

Object's kinetic energy is high on frictionless medium.

Explanation:

There is a great difference in object's kinetic energy which is present between sliding with friction and sliding without friction because friction decreases the speed of an object so if an object moves on the frictionless medium, it moves and covers more distance and we can say that the object has more kinetic energy while on the other hand, if a body moves on the medium and experience friction so it moves with little speed so we can say that the body has low kinetic energy.

Complete Question

Suppose a wireless charging system of an electric toothbrush. The charger has Solenoid 1 with 800 turns and the toothbrush has Solenoid 2 with 150 turns. The current in the charger is 220 mA and the corresponding average magnetic flux through Solenoid 2 is 0.056 Wb. What is the mutual inductance of the pair of the solenoids?

Answer:

The value is [tex]M = 38.2 \ H[/tex]

Explanation:

From the question we are told that

     The number of turns of solenoid 1 is [tex]N_1 = 800[/tex]

     The  number of turns for solenoid 2 is  [tex]N_2 = 150 \ turns[/tex]

     The current in the charger is  [tex]I = 220 \ mA = 220 *10^{-3} \ A[/tex]

      The  magnetic flux through solenoid 2 is  [tex]\phi = 0.056 \ Wb[/tex]

Generally mutual inductance is mathematically represented as

        [tex]M = \frac{N_2 * \phi }{ I }[/tex]

=>     [tex]M = \frac{150 * 0.056 }{ 220 *10^{-3} }[/tex]

=>    [tex]M = 38.2 \ H[/tex]

Work done by lifting is 3,300 Newton.

Given that;

Mass of thing = 15 kg

Height lifted = 22 m

Find:

Work done by lifting

Computation:

Work done = mgh

Work done by lifting = (15)(10)(22)

Work done by lifting = 3,300 Newton

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Answer:

The value is [tex]R_f = \frac{4}{5} R[/tex]

Explanation:

From the question we are told that

   The  initial velocity of the  proton is [tex]v_o[/tex]

    At a distance R from the nucleus the velocity is  [tex]v_1 = \frac{1}{2} v_o[/tex]

    The  velocity considered is  [tex]v_2 = \frac{1}{4} v_o[/tex]

Generally considering from initial position to a position of  distance R  from the nucleus

 Generally from the law of energy conservation we have that  

       [tex]\Delta K = \Delta P[/tex]

Here [tex]\Delta K[/tex] is the change in kinetic energy from initial position to a  position of  distance R  from the nucleus , this is mathematically represented as

      [tex]\Delta K = K__{R}} - K_i[/tex]

=>    [tex]\Delta K = \frac{1}{2} * m * v_1^2 - \frac{1}{2} * m * v_o^2[/tex]

=>    [tex]\Delta K = \frac{1}{2} * m * (\frac{1}{2} * v_o )^2 - \frac{1}{2} * m * v_o^2[/tex]

=>    [tex]\Delta K = \frac{1}{2} * m * \frac{1}{4} * v_o ^2 - \frac{1}{2} * m * v_o^2[/tex]

And  [tex]\Delta P[/tex] is the change in electric potential energy  from initial position to a  position of  distance R  from the nucleus , this is mathematically represented as

          [tex]\Delta P = P_f - P_i[/tex]

Here  [tex]P_i[/tex] is zero because the electric potential energy at the initial stage is  zero  so

             [tex]\Delta P = k * \frac{q_1 * q_2 }{R} - 0[/tex]

So

           [tex]\frac{1}{2} * m * \frac{1}{4} * v_o ^2 - \frac{1}{2} * m * v_o^2 = k * \frac{q_1 * q_2 }{R} - 0[/tex]

=>        [tex]\frac{1}{2} * m *v_0^2 [ \frac{1}{4} -1 ] = k * \frac{q_1 * q_2 }{R}[/tex]

=>        [tex]- \frac{3}{8} * m *v_0^2 = k * \frac{q_1 * q_2 }{R} ---(1 )[/tex]

Generally considering from initial position to a position of  distance [tex]R_f[/tex]  from the nucleus

Here [tex]R_f[/tex] represented the distance of the proton from the nucleus where the velocity is  [tex]\frac{1}{4} v_o[/tex]

     Generally from the law of energy conservation we have that  

       [tex]\Delta K_f = \Delta P_f[/tex]

Here [tex]\Delta K[/tex] is the change in kinetic energy from initial position to a  position of  distance R  from the nucleus  , this is mathematically represented as

      [tex]\Delta K_f = K_f - K_i[/tex]

=>    [tex]\Delta K_f = \frac{1}{2} * m * v_2^2 - \frac{1}{2} * m * v_o^2[/tex]

=>    [tex]\Delta K_f = \frac{1}{2} * m * (\frac{1}{4} * v_o )^2 - \frac{1}{2} * m * v_o^2[/tex]

=>    [tex]\Delta K_f = \frac{1}{2} * m * \frac{1}{16} * v_o ^2 - \frac{1}{2} * m * v_o^2[/tex]

And  [tex]\Delta P[/tex] is the change in electric potential energy  from initial position to a  position of  distance [tex]R_f[/tex]  from the nucleus , this is mathematically represented as

          [tex]\Delta P_f = P_f - P_i[/tex]

Here  [tex]P_i[/tex] is zero because the electric potential energy at the initial stage is  zero  so

             [tex]\Delta P_f = k * \frac{q_1 * q_2 }{R_f } - 0[/tex]      

So

          [tex]\frac{1}{2} * m * \frac{1}{8} * v_o ^2 - \frac{1}{2} * m * v_o^2 = k * \frac{q_1 * q_2 }{R_f }[/tex]

=>        [tex]\frac{1}{2} * m *v_o^2 [-\frac{15}{16} ] = k * \frac{q_1 * q_2 }{R_f }[/tex]

=>        [tex]- \frac{15}{32} * m *v_o^2 = k * \frac{q_1 * q_2 }{R_f } ---(2)[/tex]

Divide equation 2  by equation 1

              [tex]\frac{- \frac{15}{32} * m *v_o^2 }{- \frac{3}{8} * m *v_0^2 } } = \frac{k * \frac{q_1 * q_2 }{R_f } }{k * \frac{q_1 * q_2 }{R } }}[/tex]

=>           [tex]-\frac{15}{32 } * -\frac{8}{3} = \frac{R}{R_f}[/tex]

=>           [tex]\frac{5}{4} = \frac{R}{R_f}[/tex]

=>             [tex]R_f = \frac{4}{5} R[/tex]

Answer:

The longest wavelength of light needed to produce current is 567.9 nm.

Explanation:

Given;

minimum energy required to produce electric current from the cathode to anode = work function, E = 3.5 x 10⁻¹⁹ J

E = hf

[tex]E = \frac{hc}{\lambda}[/tex]

where;

c is speed of light = 3 x 10⁸ m/s

λ is the longest wavelength of light needed to produce current

[tex]E = \frac{hc}{\lambda} \\\\\lambda = \frac{hc}{E} \\\\\lambda = \frac{(6.626\times 10^{-34})(3\times 10^8)}{3.5\times 10^{-19}}\\\\\lambda = 5.679 \times 10^{-7} \ m\\\\\lambda = 567.9 \times 10^{-9} \ m\\\\\lambda = 567.9 \ nm[/tex]

Therefore, the longest wavelength of light needed to produce current is 567.9 nm.

The 1500 N force would need to act in the direction opposite the train car's movement, so if we take the current direction it's moving in to be positive, we have by Newton's second law

-1500 N = (15,000 kg) a   →   a = -0.10 m/s²

If t is the time it takes for the train to come to rest, then

-0.10 m/s² = (0 - 5.4 m/s) / t

t = (5.4 m/s) / (0.10 m/s²)   →   t = 54 s

Answer: c I think is the answer

Explanation:

Answer:

Explanation:

online personal fittness

Answer:

Answer = 6.022×10²³ molecules of CH4 which consists of 1 mole of C atoms and 4 moles of H atoms.

We are given:

Frequency of the wave = 100 Hz

Velocity of the wave = 5 m/s

Finding the Wavelength:

We know the relation between the wavelength and frequency is:

u = νλ    [where ν is the frequency, u is the speed and λ is the wavelength]

5 = 100*(λ)

λ = 5/100         [dividing both sides by 100]

λ = 1/20

λ = 0.05 m

Hence, the wavelength is 0.05 m

Let, frictional force is f and normal force is N.

Balancing horizontal forces :

[tex]50cos \ 30^o - f = 12 \times 4.13\\\\f = 50cos \ 30^o - 49.56\\\\f = -6.26\ N[/tex]

Also, balancing vertical forces, we get :

[tex]N = mg + 50sin \ 30^o\\\\N =( 12\times 9.8 ) + (50\times sin \ 30^o)\\\\N = 142.6\ N[/tex]

Therefore, the frictional force and normal force is -6.26 N and 142.6 N.

Answer:

B)

Explanation:

The answer is B)- The object's speed must be changing.

So will I get the Brainliest...

Answer:

1.1x10^-2N

Explanation:

We have the change in momentum as

P = 0.3(4.5+12)g.mph

= 0.3x0.447x(4.5+12)x10^-3

Then the force that is exerted will be

F = p/∆t

∆t = 0.2

= 0.3x0.447x(4.5+12)x10^-3/0.2

= 0.1341x16.5x10^-3/0.2

= 1.1x10^-2

Therefore the force that was exerted is equal to 1.1x10^-2

The required magnitude of the force exerted on the fly is of [tex]5.025 \times 10^{-3} \;\rm N[/tex].

Given data:

The mass of mosquito is, [tex]m =0.3 \;\rm g =3 \times 10^{-4} \;\rm kg[/tex]

The speed of flying is, u = 4.5 mph = 4.5 ( 0.447) = 2.01 m/s.

The swatting speed of mosquito is, v = 12 mph = 12 (0.447 ) = 5.36 m/s.

The time of contact is, t = 0.2 s.

In this problem, we will first calculate the change in momentum, and the change in momentum is given as,

p = m ( v - u)

Solving as,

[tex]p = 3 \times 10^{-4} (5.36 - 2.01)\\\\p = 1.005 \times 10^{-3} \;\rm kg.m/s[/tex]

Now as per the Newton's second law,

[tex]F = p/t\\\\F = 1.005 \times 10^{-3} / 0.2\\\\F= 5.025 \times 10^{-3} \;\rm N[/tex]

Thus, the required magnitude of the force exerted on the fly is of [tex]5.025 \times 10^{-3} \;\rm N[/tex].

Learn more about the Newton's second law here:

https://brainly.com/question/19860811

Answer:

Of course we feel bad or angry.

Explanation:

that it what i know....

Answer:

1. False

2. Fats

3. False

Explanation:

MyPlate is an initiative from the United States Department of Agriculture that is designed to help Americans improve their eating habits throughout their lifetimes. Every meal matters. The five food groups represented in My Plate include vegetables, grain, dairy, protein foods, and fruits.

Calories are a source of energy for the human body. So, the more active a person is, the more energy he would need to be supplied to him in form of calories. The less active a person is, the fewer calories he would need.

Answer: the angle between the resultant vector and the vector of the 18 pound is 28°

Explanation:

given that data in the question; as its interpreted in the diagram below;

from the cosine rule, we know that;

a² = b² + c² - 2bc  

so

(13)² = (6)² + (18)² - (2 × 6 × 18 ) cos∅

169 = 36 + 324 - 216cos∅

169 = 360 - 216cos∅

216cos∅ = 360 - 169

216cos∅ = 191

cos∅ = 0.8842

∅ = cos⁻¹ ( 0.8842 )

∅ = 27.8° ≈ 28°  {nearest whole number}

Therefore the angle between the resultant vector and the vector of the 18 pound is 28°

Answer:

Explanation:

The Spanish flu pandemic of 1918, the deadliest in history, infected an estimated 500 million people worldwide about one-third of the planet’s population and killed an estimated 20 million to 50 million victims, including some 675,000 Americans. The 1918 flu was first observed in Europe, the United States and parts of Asia before swiftly spreading around the world. At the time, there were no effective drugs or vaccines to treat this killer flu strain. Citizens were ordered to wear masks, schools, theaters and businesses were shuttered and bodies piled up in makeshift morgues.

Does this sound familiar?

Its the same thing but with a different name called the Corona virus pandemic the same thing happened in 1918 and now it is happening again in 2020 , but in in 2020 there are far less people infected by the Corona virus as compared to the Spanish flu the numbers approximate around 70 million infected and deaths are around 2 million.

The rapid spread of Spanish flu in the fall of 1918 was at least partially to blame on public health officials unwilling to impose quarantines during wartime. The public health response to the crisis in the United States was further hampered by a severe nursing shortage as thousands of nurses had been deployed to military camps and the front lines. But one of the chief reasons that the Spanish flu claimed so many lives in 1918 was that science simply didn’t have the tools to develop a vaccine for the virus. Microscopes couldn’t even see something as incredibly small as a virus until the 1930s.

That is why the Spanish Flu claimed so many lives in 1918 and the Corona Virus didn't claim that many.

The Corona Virus patients with respect to Spanish Flu patients exponentially decreased because in 2020 we had the specific tools to fight the virus and since mankind was aware when the world engrossed into the pandemic 100 years before the new the risks that it could impose on the world , People started to Quarantine themselves, more nurses/doctors are available rather than in the era of the 19th century.

Mathematically we would say that the exponential growth would be:

[tex]y=ab^x[/tex]

This is an exponential function, which means as you increase  x , y  increases exponentially, and where a is the initial value and b is the growth factor.

For example:

There are 100,000 cases of Coronavirus when the virus outbroke. If the number of cases doubles every week then how many cases would be there in 10 weeks?

So the solution would be

[tex]y=ab^x\\y=100000(2)^{10}\\y=102400000[/tex]

Which means people infected with the virus would be approximate 102.5 million. But since this kind of pandemic already broke out in 1918 called the Spanish flu mankind was wise and controlled its growth factor (b) by Quarantining people , shutting down businesses, schools  and implying them to work from home , closing off cafeteria's restaurants for dine in purposes and just allowing take away to reduce human contact, and since 1918 we have more doctors and nurses to treat the infected in 2020 we reduced the outbreak to 70 million in about 10 months other wise it could have been 100 million in just 2.5 months as we can see.

So guys stay indoors just go out if you REALLY need something, avoid meeting others , wear masks and gloves :)

Answer:

The value is  [tex]\alpha = 3.84 \ rad/s^2[/tex]

Explanation:

From the question we are told that

    The constant angular speed is  [tex]w = 11.9 \ rad/s[/tex]

     The time taken is  [tex]t = 3.10 \ s[/tex]

Generally the magnitude of the angular acceleration is  mathematically represented as  

          [tex]\alpha = \frac{w}{t}[/tex]

=>     [tex]\alpha = \frac{11.9}{ 3.10 }[/tex]

=>     [tex]\alpha = 3.84 \ rad/s^2[/tex]

Answer:

D

Explanation:

The object will remain motionless(i just need points)

Answer:

Graph for object that is not moving: B

Graph for object that is speeding up: D

Explanation:

A.) In order to represent that an object is not moving, you must either show that there is no velocity (0 m/s) or show a position over time graph that is a horizontal line.

Because the position is the same as time increases, the graph shows that there the object must be at rest, as there is no change in position due to velocity. (Velocity must be 0m/s)

B.) In order to represent an object is speeding up, the position time graph must either be a positive exponential function, the velocity time graph must be a positive, linear line, or the acceleration over time graph must be a positive, horizontal line.

Why is D the correct answer? Because if an object is speeding up, you know that the value of its speed (velocity) is increasing at some rate. And since speeding up refers to positive change, the function of velocity over time graph must be a positive function.

You need to know the coefficient of static friction between a wooden object and a wooden surface. I'll denote it with µ. If you're given a specific value you should obviously use that.

By Newton's second law, the horizontal and vertical net forces are

• net horizontal:

∑ F = p - f = 0

• net vertical:

∑ F = n - w = 0

where

p = magnitude of the pushing force

f = mag. of friction

n = mag. of the normal force

w = weight of the crate

The second equation gives

n = w = (5 kg) (9.8 m/s²) = 49 N

Friction is proportional to the normal force by a factor of µ, so

f = µ (49 N) = 49µ N

To overcome static friction, the push has to exceed this in magnitude, so that

p > 49µ N

For instance, if p = 0.25, then p would need to greater than 12.25 N. (This example isn't particularly helpful, though, since both possibly correct options are larger than 12.25 N...)

Answer:

A. Atoms are the smallest unit of an element.

Explanation:

The correct statement from the given choices is that atoms are the smallest unit of an element.

Atoms are the smallest particles that takes part in chemical reactions and they are made up of protons, neutrons and electrons.

Answer:

because theres is not enough friction so it will be super slippery

Explanation:

Answer:

The car starts moving in the positive direction at x = 0.2 seconds. Initially it moves very little, but it covers a greater distance with each time increment.

Explanation:

Answer:  The car starts moving in the positive direction at x = 0.2 seconds. Initially it moves very little, but it covers a greater distance with each time increment.

Explanation: edmentum sample answer

Answer:

1400.38N

Explanation:

Step one

Given data

P1= 250N

D1= 0.02m

A1= πD1^2/4

substitute

[tex]A1= 3.142*0.02^2/4\\\\A1=3.142*10^-4[/tex]

D2= 0.15m

A1= πD2^2/4

[tex]A2= 3.142*0.15^2/4\\\\A2=1.76*10^-3[/tex]

Required

The load P2

Step two:

Applying the hydraulic expression for a non-compressible fluid

we know that

Pressure= force/are

P1/A1=P2/A2

[tex]250/3.142*10^-4= P2/1.76*10^-3[/tex]

cross multiply we have

P2= 1.76*10^-3*250/3.142*10^-4

P2=0.44/3.142*10^-4

P2=1400.38N

Answer:

2.92 m/s

Explanation:

For the entire motion, the average velocity (V) can be calculated thus;

V = [tex]\frac{displacement}{time}[/tex]

Total displacement of the player = 10.0 + (-5) + 17.2

        = 22.2 m

Total time = 2.00 + 1.50 + 4.10

         = 7.60 s

V = 22.2/7.60

       = 2.92 m/s

Hence, the velocity of the players for the entire motion is 2.92 m/s.

Answer:

I think it's c or A hopes this help