Please help!!
A person is driving in a circle at 20m/s. Are they accelerating?

Answer:

-240

Explanation:

A motorcycle skids for a distance of 2.0 m on an icy road, then the change in kinetic energy for the motorcycle will be equal to -240 J.

The force which a moving object has is referred to as kinetic energy in physics. It is defined as the number of effort required to propel a person of a specific mass from still to a specific velocity.

Aside from slight fluctuations in speed, your body holds onto the kinetic energy it obtains during acceleration.

When the body slows down from its present level to a condition of rest, the same quantity of energy is used.

Formally, kinetic energy is any quantity that has a gradient concerning time in the Lagrangian of a system.

As per the given information in the question,

Distance, d = 2.0 m

Friction, f = 120 N

The angle between displacement and friction force, θ = 180°

Now, the change in kinetic energy for the motorcycle = Work done by the friction.

K.E = f × d(cos θ)

= 120 (2.0 m)(cos 180°)

Δ K.E = -240 J

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Answer:

E = 3600 J

Explanation:

Given that,

Voltage, V = 115 V

Power of electric bulb, P = 60 W

We need to find the electric energy used in 1 minute. The electric energy use is given by :

[tex]E=P\times t\\\\E=60\ W\times 60\ s\\\\E = 3600\ J[/tex]

Hence, the electrical energy is 3600 J.

Answer: Age

Explanation:

Physical fitness has to do with the effective and efficient working of the body system which allows individuals to be healthy.

The factors that are critical in developing good physical fitness include the environment, the behavior of the individual and heredity. To maintain physical fitness, one should exercise, eat healthy, avoid smoking etc. Age is not a factor in physical fitness.

Answer:

i kinda dnt knw srry wanted the points for the answer

Explanation:

Answer:

a

  [tex]\lambda = 202.7 \ m[/tex]

b

  [tex]w = 9.3 *10^{6} \ rad/s[/tex]

c

  [tex]k = 0.031 m^{-1}[/tex]

d

  [tex]E_{max} = 9.0 *10^{-3} \ V/m[/tex]

Explanation:

From the question we are told that  

       The frequency of the radio station is  [tex]f= 1480 \ kHz = 1480 *10^{3}\ Hz[/tex]

         The magnitude of the magnetic field is  [tex]B = 3.0* 10^{-11} \ T[/tex]

Generally the wavelength is mathematically represented as

          [tex]\lambda = \frac{c}{f}[/tex]

Here c is the speed of light with value  [tex]c = 3.0 *10^{8} \ m/s[/tex]

So

        [tex]\lambda = \frac{3.0 *10^{8}}{ 1480 *10^{3}}[/tex]

=>      [tex]\lambda = 202.7 \ m[/tex]

Generally the angular frequency is mathematically represented as

       [tex]w = 2 \pi * f[/tex]

=>   [tex]w = 2 * 3.142 * 1480 *10^{3}[/tex]

=>   [tex]w = 9.3 *10^{6} \ rad/s[/tex]

Generally the wave number is mathematically represented as        

=>      [tex]k = \frac{2 \pi }{\lambda}[/tex]

=>      [tex]k = \frac{2 * 3.142 }{ 202.7}[/tex]

=>      [tex]k = 0.031 m^{-1}[/tex]

Generally the amplitude of the electric field at this distance from the transmitter is mathematically represented as

         [tex]E_{max} = c * B[/tex]

=>      [tex]E_{max} = 3.0 *10^{8} * 3.0* 10^{-11}[/tex]

=>      [tex]E_{max} = 9.0 *10^{-3} \ V/m[/tex]

[tex] \underline{\purple{\large \sf Combination \: reaction :-}} [/tex]

Those reaction in which two or more substances combine to form a one new substance are called Combination reaction

In this reaction, We can add :

[tex] \underline{\green{\large \sf For\: example :}} [/tex]

[tex] \sf 2H_{2} + O_{2} \: \underrightarrow{Combination} \: 2H_{2}o[/tex]

In this, Hydrogen is an element and Oxygen is another element. Both are combined to form compound 'Hydrogen oxide'. Hydrogen oxide is commonly known as water.

In an open circuit like the picture the light bulb will be off. So, option (C) is correct.

Electric circuit is a way for current to flow through electricity. An electric circuit consists of a source of energy for the charged particles that make up the current, like a battery or generator; sources of current-using equipment, like lamps, electric motors, or computers; and the connecting wires or transmission lines.

Ohm's law and Kirchhoff's rules are two of the fundamental mathematical laws that define how electric circuits function.

In the given diagram, the circuit is open. So, no current passes through it and the light bulb will be off. Hence, option (C) is correct.

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Answer:

c. because A will land first becuase its heavier

Explanation:

Given :

A copper plate of mass 3.0g.

Atomic number, z = 29.

Atomic mass, M.M = 63.5 g/mol.

Avogadro's number, [tex]N_a = 6.02\times 10^{23}\ atoms[/tex].

Charge on electron, [tex]e = 1.6\times 10^{-19}\ C[/tex].

To Find :

The total charge of all the electrons.

Solution :

Moles of copper,

[tex]m = \dfrac{3}{63.5}\ moles\\\\m = 0.047 \ moles[/tex]

Number of atoms in 0.047 moles of copper :

[tex]n = 0.047\times 6.02\times 10^{23}\\\\n = 2.83\times 10^{22} \ atoms[/tex]

Since, there are 29 electrons on each atoms.

So, total charge is :

[tex]C = 2.83\times 10^{22}\times 29\times 1.6\times 10^{-19}\ C\\\\C = 131312\ C\\\\C = 1.31 \times 10^5\ C[/tex]

Hence, this is the required solution.

Answer:

2.1 m/s

Explanation:

According to law of conservation of momentum;

m1u1 + m2u2 = (m1+m2)v

m1 and m2 are the masses

u1 and u2 are the initial velocities

v is the common velocity

Given

m1 = 2150kg

m2 = 3250kg

u1 = 10.0m/s

u2 = ?

v = 5.22m/s

Substitute and get u2

2150(10) + 3250u2 = (2150+3250)5.22

21,500 + 3250u2 = 5400(5.22)

3250u2 = 28,188 - 21500

3250u2 = 6688

u2 = 6688/3250

u2 = 2.1 m/s

Hence the 3250 kg car’s initial velocity has an initial velocity of  2.1 m/s

Answer:

yes

Explanation:

yes

Answer:

that's true

Explanation:

if the rough inclined plane was rough enough than it would be true

Answer:

Both experienced the same magnitude impulse

Explanation:

This is because, the impulse force is internal to the system of both the tennis ball and the bowling ball. It is an action-reaction pair. So, the force exerted on the tennis ball by the bowling ball equals in magnitude to the force exerted by the tennis ball on the bowling ball although, they are in opposite directions. This, both experienced the same magnitude impulse.

Answer:

all are true so d is right

Explanation:

Electromagnets use electrlcity and magnets is true.

Magnetic fields are strongest around the poles of a magnet is true.

The south pole of a magnet will repel the south pole of another magnet is true

and since all of them is true the answer is d all of the above

Answer:

a = 0.1 m/s²

Explanation:

       [tex]F_{net} = F_{app} -F_{frk} = 100 N - 70 N = 30 N (1)[/tex]

       [tex]F_{net} = m* a = 300 Kg * a = 30 N (2)[/tex]

        [tex]a = \frac{F_{net}}{m} = \frac{30 N}{300kg} = 0.1 m/s2 (3)[/tex]

The power required by the car if a 1430 kg car speeds up from rest to 14.0 m/s in 7.00 s is 20020 Joules.

In science and engineering, power is the rate at which work is completed or energy is delivered. It can be expressed as the product of the work completed (W) or the energy transferred (E) divided by the time interval (t), or W/t.

A high-powered motor can complete a given amount of work quickly, or a low-powered motor can accomplish it slowly. Foot-pounds per minute, joules per second (or watts), and ergs per second are examples of units of power, which measure work (or energy) per unit of time.

Given:

A 1430 kg car speeds up from rest to 14.0 m/s in 7.00 s,

Calculate the acceleration and displacement as shown below,

[tex]v = u + at[/tex]

14 =  0 + a × 7

a = 2 m/s²

[tex]s = ut + 1/2at^2[/tex]

s = 0 + 1 / 2 × 2 × 7²

s = 49 m,

Calculate the power as shown below,

Power = 1430 × 2 × 49 / 7

Power = 20020 Joules

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Unclear/incomplete question. However, I inferred you need an explanation of the phenomenon of rainfall​.

Explanation:

Basically, the phenomenon of rainfall​ follows a natural cycle called the water cycle. What we call 'rainfall' occurs when water condensed (in liquid form) in the atmosphere is made to fall down on the ground as tiny droplets as a result of the forces of gravity.

The water cycle makes rainfall possible:

Answer:1st

Explanation:and object in motion stays in motion unless acted upon by another object

Two figure skaters skate toward each other then push of each other's hands sending them spinning in the opposite direction opposite; - This is Newton's 3rd law of motion. Hence, option (C) is correct.

Newton's third law states that if object A exerts a force on object B, then object B must apply a force to object A that is equal in magnitude and directed in the opposite direction.

This law illustrates a symmetry in nature whereby forces always occur in pairs and whereby no body can exert a force without also being subjected to one.

When two figure skaters skate toward each other then push of each other's hands, they applied force on each other. As according to  Newton's third law of motion every action has equal and opposite reaction, they  moves the opposite direction opposite.

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it would be the 3rd one. so C

Answer:

A) Z-1

Explanation:

when a radioactive element of atomic number Z emits an alpha particle, the mass of the new nucleus decreases by 2, i.e the new atomic number of the element = ( Z- 2).

Also, when the daughter nucleus emits a beta particle, the new nucleus increases by 1,  that is the new atomic number of the element = (Z + 1).

Thus, the atomic number of resulting nuclide = Z ( - 2) + ( + 1).

                                                                           = Z - 2 + 1

                                                                           = Z - 1

Therefore, the atomic number of resulting nuclide is Z - 1

Answer:

40N in either direction is the answer

Answer:

A

   [tex]N = 1340.86 \ slits / cm[/tex]

B

    [tex]\theta = 15.7^o[/tex]

Explanation:

From the question we are told that  

      The wavelength is  [tex]\lambda = 650 \ nm = 650 *10^{-9} \ m[/tex]  

        The angle of  first bright fringe is  [tex]\theta = 5^o[/tex]  

        The order of the fringe considered is  n  =1

Generally the condition for constructive interference is  

       [tex]dsin (\theta ) = n * \lambda[/tex]

=>    [tex]d = \frac{1 * 650 *10^{-9 }}{ sin(5)}[/tex]

=>    [tex]d = 7.458 *10^{-6} \ m[/tex]

Converting to cm

           [tex]d = 7.458 *10^{-6} \ m = 7.458 *10^{-6} * 100 = 0.0007458 \ cm[/tex]

Generally the number of grating pre centimeter is  mathematically represented as

           [tex]N = \frac{1}{d}[/tex]

=>         [tex]N = \frac{1}{0.0007458}[/tex]

=>         [tex]N = 1340.86 \ slits / cm[/tex]

Considering question B  

   From the question we are told that

     The first wavelength is  [tex]\lambda_1 = 650 \ nm = 650 *10^{-9} \ m[/tex]

     The second wavelength is  [tex]\lambda_2 = 429 \ m = 420 *10^{-9 } \ m[/tex]

      The order of the fringe is  [tex]n = 2[/tex]

       The grating is  [tex]N = 5000 \ slits / cm[/tex]

Generally the slit width is mathematically represented as

              [tex]d = \frac{1}{N }[/tex]

=>          [tex]d = \frac{1}{ 5000 }[/tex]

=>          [tex]d = 0.0002 \ c m = 2.0 *10^{-6} \ m[/tex]

Generally the condition for constructive interference for the first ray is mathematically represented as

         [tex]d sin(\theta_1) = n * \lambda_1[/tex]

=>      [tex]\theta_1 = sin^{-1} [\frac{ 2 * \lambda }{d}][/tex]

=>       [tex]\theta_1 = sin^{-1} [\frac{ 2 * 650 *10^{-9} }{ 2*10^{-6}}][/tex]

=>        [tex]\theta_1 = 40.5 ^o[/tex]

Generally the condition for constructive interference for the second ray is mathematically represented as

         [tex]d sin(\theta_2) = n * \lambda_2[/tex]

=>      [tex]\theta_2 = sin^{-1} [\frac{ 2 * \lambda_1 }{d}][/tex]

=>       [tex]\theta_2 = sin^{-1} [\frac{ 2 * 420 *10^{-9} }{ 2*10^{-6}}][/tex]

=>        [tex]\theta_2 = 24.8 ^o[/tex]

Generally the angular separation is mathematically represented as

            [tex]\theta = \theta_1 - \theta_1[/tex]

=>          [tex]\theta = 42.5^o - 24.8^o[/tex]

=>          [tex]\theta = 15.7^o[/tex]

Answer: Kids learn about the types of electromagnetic waves in the science of physics ... Microwaves are useful in communication because they can penetrate clouds, ... These are the infrared waves that are used in your TV remote to change channels

Explanation:

Answer:

The disk covers a rotation of 90º after 3 seconds.

Explanation:

Since the disk rotates at constant angular speed, we can determine the change in angular position ([tex]\Delta \theta[/tex]), measured in sexagesimal degrees, by the following kinematic formula:

[tex]\Delta \theta = \omega\cdot \Delta t[/tex] (1)

Where:

[tex]\omega[/tex] - Angular velocity, measured in sexagesimal degrees per second.

[tex]\Delta t[/tex] - Time, measured in seconds.

If we know that [tex]\omega= 30\,\frac{\circ}{s}[/tex] and [tex]\Delta t = 3\,s[/tex], then the change in angular position is:

[tex]\Delta \theta = \left(30\,\frac{\circ}{s} \right)\cdot (3\,s)[/tex]

[tex]\Delta \theta = 90^{\circ}[/tex]

The disk covers a rotation of 90º after 3 seconds.

Answer:

12445 J

Explanation:

Given that

Power output, P = 5 kW

efficiency of the engine, e = 27% = 0.27

Thermal energy expelled, Q(c) = 9085 J

Heat absorbed, Q(h) = ?

Using the formula

e = W/Q(h)

e = [Q(h) - Q(c)] / Q(h)

e = 1 - Q(c)/Q(h)

Now, substituting the values into the formula, we have

0.27 = 1 - 9085/Q(h)

9085/Q(h) = 1 - 0.27

9085/Q(h) = 0.73

Q(h) = 9085 / 0.73

Q(h) = 12445 J

Thus, the heat absorbed is 12445 J

Answer:

The value is  [tex]\mu_k = 0.102[/tex]

Explanation:

From the question we are told that

   The initial speed of the pluck is  [tex]u = 10 \ m/s[/tex]

    The  distance it slides on the horizontal ice is  [tex]s = 50 \ m[/tex]

Generally from kinematic equation we have that

       [tex]v^2 = u^2 + 2as[/tex]      

Here v is  is the final velocity and the value is 0 m/s given that the pluck came to rest, so

      [tex]0^2 = 10 ^2 + 2* a * 50[/tex]      

=>   [tex]a = - 1 \ m/s^2[/tex]

Here the negative sign show that the pluck is decelerating  

 Generally the force applied on the pluck is  equal to the frictional force experienced by the pluck

      So  

                [tex]F = F_f[/tex]

=>            [tex]m * a = m* g * \mu_k[/tex]

=>             [tex]1 = 9.8 * \mu_k[/tex]

=>              [tex]\mu_k = 0.102[/tex]

Answer:

16.

Explanation:

        [tex]v = \lambda * f (1)[/tex]

        [tex]\lambda = \frac{v}{f} = \frac{130m/s}{215 hz} = 0.61 m (2)[/tex]

       [tex]n = \frac{L}{\lambda} = \frac{10.0m}{0.61m} = 16.4 (3)[/tex]

The exercise involves filling in the gaps with the possible wave

properties that can be obtained from a spring.

The correctly completed exercise is presented as follows;

A wave is a disturbance that moves through a medium. There are two

types of waves. A mechanical wave requires matter to travel. List some

examples of this type: sound wave, water wave, spring waves.

A electromagnetic wave does not require a medium. Examples include: Light waves

In order to start and transmit a mechanical wave, a source of

disturbance and a physical medium are required. A single disturbance is

referred to as a pulse, and a series of disturbance is a wave train.

This type of wave is called transverse wave. Its pulses are called crest

and troughs.

Now send a pulse by quickly pushing the spring forward and pulling it

back, as shown. This type of wave is called longitudinal wave. Watch the

motion of the ribbon. In this type, the particles move parallel to the

direction the wave travels. Its pulses are called compression and

rarefactions. Note that all waves transfer energy without transferring

matter. In mechanical waves, particle of the medium vibrate back and

forth in simple harmonic motion while the disturbance (or energy)

moves from one place to another.

B. Wave speed

Does the pulse catch up to the other? yes. The size of the pulse is called

the amplitude of the wave.

Did the size of the pulse affect the speed? No.

The average time wave it takes the wave to travel

Without changing your positions therefore keeping the distance the

pulse travels the same), pull the slinky tighter using only about 3/4 of

coils. This makes a completely different medium through which the

pulse will travel. Time the journey as before time record. Does the kind

of medium affect the speed of the pulse? Yes

C. Wavelength and Frequency

High frequency waves have short wavelengths and low frequency waves

have long wavelengths.

The speed of a wave in any medium is equal to the frequency of the wave × the wavelength. This wave equation [tex]\underline{f = \dfrac{v}{\lambda } }[/tex] shows that f and λ are

inversely proportional. The units of the variables are;

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