If an electron is accelerated from rest through a potential difference of 1.60 x 102V, what is its de Broglie wavelength

Answer:

Explanation:

Formula used for calculating power P = current * voltage

P = IV

From ohms law, V = IR where R is the resistance. Substituting V = IR into the formula for calculating power, we will have;

P = IV

P =(V/R)V

P = V²/R

Given parameters

Power rating of the bulb P = 100 Watts

Source voltage V = 110V

Required

Resistance of the bulb R

Substituting the given parameters into the formula for calculating power to get Resistance R;

P = V²/R

100 = 110²/R

R = 110²/100

R = 110 * 110/100

R = 12100/100

R = 121 ohms

Hence, the resistance of this bulb is 121 ohms

Answer:

[tex]r=4.24\times 10^{11}\ m[/tex]

Explanation:

Given that,

Orbital time period, T = 3.75 earth years

Mass of star, [tex]m=3.23\times 10^{30}\ kg[/tex]

We need to find the radius of the exoplanet's orbit. It is a concept of Kepler's third law of motion i.e.

[tex]T^2=\dfrac{4\pi^2}{GM}r^3[/tex]

r is the radius of the exoplanet's orbit.

Solving for r we get :

[tex]r=(\dfrac{T^2GM}{4\pi^2})^{1/3}[/tex]

We know that, [tex]1\ \text{earth year}=3.154\times 10^7\ \text{s}[/tex]

So,

[tex]r=(\dfrac{(3.75\times 3.154\times 10^7)^2\times 6.67\times 10^{-11}\times 3.23\times 10^{30}}{4\pi^2})^{1/3}\\\\r=4.24\times 10^{11}\ m[/tex]

So, the radius of the exoplanet's orbit is [tex]4.24\times 10^{11}\ m[/tex].

Answer: μ = 0.8885

Explanation: Force due to friction is calculated as: [tex]F_{f} = \mu.N[/tex]

At an inclined plane, normal force (N) is: N = mgcosθ, in which θ=32.51.

Power associated with work done by friction is [tex]P=F_{f}.x[/tex]. The variable x is displacement the object "spent its energy".

Power associated with work done by gravitational force is P = mghcosθ, where h is height.

The decline forms with horizontal plane a triangle as draw in the picture.

To determine force due to friction:

[tex]F_{f}.x=mghcos(\theta)[/tex]

[tex]F_{f}=\frac{mghcos(\theta)}{x}[/tex]

Replacing force:

[tex]\frac{m.g.h.cos(\theta)}{x} = \mu.m.g.cos(\theta)[/tex]

[tex]\mu=\frac{h}{x}[/tex]

Calculating h using trigonometric relations:

[tex]sin(32.51) = \frac{h}{1}[/tex]

h = sin(32.51)

Coefficient of Kinetic friction is

[tex]\mu=\frac{sin(32.51)}{1}[/tex]

μ = 0.8885

For these conditions, coefficient of kinetic friction is μ = 0.8885.

Answer:

C. Neither ultrasonic nor infrasonic vibrations can be heard by humans.

Explanation:

The complete question is

Which of the following statements is true of vibrations? A. The frequency of infrasonic vibrations is much too high to be heard by humans. B. Ultrasonic vibrations have a frequency lower than the range for normal hearing. C. Neither ultrasonic nor infrasonic vibrations can be heard by humans. D. Infrasonic vibrations are used in sonar equipment and to detect flaws in steel castings.

Ultrasonic vibrations have frequencies higher than our range of hearing, while infrasonic vibrations have frequencies lower than our range of hearing. Ultrasonic vibrations or sound is used in sonar equipment, and is used for detecting hidden flaws in steel castings and structures. Both infrasonic and ultrasonic fall below and above our normal hearing range respectively, and are only audible to dogs, cats, and some other mammals.

Answer:

Answer is " Two bodies with the same vibration frequency that are placed next to each other will exhibit sympathetic vibrations as one body causes the other to vibrate."

Explanation:

My options were:

A)  Forced vibrations, such as those between a tuning fork and a large cabinet surface, result in a much lower sound than was produced by the original vibrating body.

B)  Resonance occurs as a result of sympathetic vibrations.

C)  A non-vibrating object can begin to vibrate as a result of forced vibrations.

D)  Two bodies with the same vibration frequency that are placed next to each other will exhibit sympathetic vibrations as one body causes the other to vibrate.

A is correct

.

Answer:

they must be affordable because they have to pay for it or they wont get the stuff they are bying.

Explanation:

need a brainliest please.

Answer: B, they must be affordable.

Explanation:

Answer:

a) m = 0.626 kg , b) T = 2.09 s , c)   a = 1.0544 m / s²

Explanation:

In a spring mass system the equation of motion is

        x = A cos (wt + Ф)

with      w = √(k / m)

a) velocity is defined by

        v = dx / dt

        v = - A w sin (wt + Ф)          (1)

give us that the speed is

        v = 26.1 m / s

for the point

        x = a / 2

the range of motion is a = 11.0 cm

       x = 11.0 / 2

       x = 5.5 cm

Let's find the time it takes to get to this distance

       wt + Ф = cos⁻¹ (x / A)

       wt + Ф = cos 0.5

        wt + Ф = 0.877

In the exercise they do not indicate that the body started its movement with any speed, therefore we assume that for the maximum elongation the body was released, therefore the phase is zero f

       Ф = 0

       wt = 0.877

       t = 0.877 / w

we substitute in equation 1

       26.1 = -11.0 w sin (w 0.877 / w)

        w = 26.1 / (11 sin 0.877))

        w = 3.096 rad / s

from the angular velocity equation

       w² = k / m

       m = k / w²

       m = 6 / 3,096²

       m = 0.626 kg

b) angular velocity and frequency are related

       w = 2π f

frequency and period are related

        f = 1 / T

we substitute

        w = 2π / T

        T = 2π / w

        T = 2π / 3,096

        T = 2.09 s

c) maximum acceleration

 the acceleration of defined by

        a = dv / dt

        a = - Aw² cos (wt)

the acceleration is maximum when the cosine is ±1

         a = A w²

          a = 11  3,096²

        a = 105.44 cm / s²

we reduce to m / s

        a = 1.0544 m / s²

Answer:

The self-inductance in henries for the solenoid is 0.0274 H.

Explanation:

Given;

number of turns, N = 1500 turns

length of the solenoid, L = 13 cm = 0.13 m

radius of the wire, r = 2 cm = 0.02 m

The self-inductance in henries for a solenoid is given by;

[tex]L = \frac{\mu_oN^2A}{l}[/tex]

where;

[tex]\mu_o[/tex] is permeability of free space = [tex]4\pi*10^{-7} \ H/m[/tex]

A is the area of the solenoid = πr² = π(0.02)² = 0.00126 m²

[tex]L = \frac{4\pi *10^{-7}(1500)^2*(0.00126)}{0.13} \\\\L = 0.0274 \ H[/tex]

Therefore, the self-inductance in henries for the solenoid is 0.0274 H.

Answer:

Wavelength is 471 nm

Explanation:

Given that,

Lines per unit length of diffraction grating is 500 lines/mm.

The third maxima from the central maxima (m=3) is at an angle of 45°

We need to find the color of laser light shines through a diffraction grating.

The condition for maxima is :

[tex]d\sin\theta=m\lambda[/tex]

d = 1/N, N = number of lines per mm

[tex]\lambda=\dfrac{1}{Nm}\sin\theta\\\\\lambda=\dfrac{10^{-3}}{500\times 3}\sin(45)\\\\\lambda=4.31\times 10^{-7}\\\\\text{or}\\\\\lambda=471\ nm[/tex]

Answer:

Knowledge of vectors is important because many quantities used in physics are vectors. If you try to add together vector quantities without taking into account their direction you'll get results that are incorrect.

Explanation:

An example of the importance of vector addition could be the following:

Two cars are involved in a collision. At the time of the collision car A was travelling at 40 mph, car B was travelling at 60 mph. Until I tell you in which directions the cars were travelling you don't know how serious the collision was.

The cars could have been travelling in the same direction, in which case car B crashed into the back of car A, and the relative velocity between them was 20 mph. Or the cars could have been travelling in opposite directions, in which case it was a head on collision with a relative velocity between the cars of 100 mph!

0.6764*10^-10m

Explanation:

Using E= hc/wavelength

(4.14x10^-15)x(3.0x10^8)/(65x10^-12)=0.1911x10^5 eV=19.1 keV

So subtract the calculated energy from the given energy of scattered photons

9.11-0.75=18.36 keV

To find wavelength

Wavelength= hc/ E

[(4.14x 10^-15)x (3.0x10^8)]/(18.36*10^3) =0.6764^-10 m

Answer:

Explanation:

Christian Huygens

Light Is a Wave!

Then, in 1678, Dutch physicist Christian Huygens (1629 to 1695) established the wave theory of light and announced the Huygens' principle.

Answer:

Explanation:

Friction is defined as a force which acts at the surface of separation between two objects in contact and tends to oppose motion of one over the other.

While kinetic friction is the force that must be overcome so that a body can move with uniform speed over another.

Hence let consider one of the laws of friction which states that: '' Frictional force is independent of the area of the surfaces in contact.''

The value did not vary with area. This is because when calculating the kinetic fiction, the total contact area is not relevant and only the total weight of the system as well of as the block is put into consideration.

Answer:

a

    [tex]z= 2.5 \ m[/tex]

b

   [tex]z = (1 \ m , 4 \ m )[/tex]

Explanation:

From the question we are told that

     Their distance apart is  [tex]d = 5.00 \ m[/tex]

      The  wavelength of each source wave [tex]\lambda = 6.0 \ m[/tex]

Let the distance from source A  where the construct interference occurred be z

Generally the path difference for constructive interference is

              [tex]z - (d-z) = m \lambda[/tex]

Now given that we are considering just the straight line (i.e  points along the line connecting the two sources ) then the order of the maxima m =  0

  so

        [tex]z - (5-z) = 0[/tex]

=>     [tex]2 z - 5 = 0[/tex]

=>     [tex]z= 2.5 \ m[/tex]

Generally the path difference for destructive  interference is

           [tex]|z-(d-z)| = (2m + 1)\frac{\lambda}{2}[/tex]

=>         [tex]|2z - d |= (0 + 1)\frac{\lambda}{2}[/tex]

=>        [tex]|2z - d| =\frac{\lambda}{2}[/tex]

substituting values

          [tex]|2z - 5| =\frac{6}{2}[/tex]

=>      [tex]z = \frac{5 \pm 3}{2}[/tex]

So  

      [tex]z = \frac{5 + 3}{2}[/tex]

      [tex]z = 4\ m[/tex]

and

      [tex]z = \frac{ 5 -3 }{2}[/tex]

=>   [tex]z = 1 \ m[/tex]

=>    [tex]z = (1 \ m , 4 \ m )[/tex]

Answer:

1. Transformer 3> Transformer 1 and 2 > Transformer 4

2. Transformer 2,3,5 > Transformer 1 > Transformer 4

Explanation:

From;

Vs/Vp = Ns/Np

Where;

Vp= voltage in primary coil

Vs= voltage in secondary coil

Ns= number of turns in secondary coil

Np= number of turns in primary coil.

Vs= Ns×Vp/Np

Vs= 480 ×2000/4000

Vs= 240 V

Vs= 480 ×1000/2000

Vs=240 V

Vs= 120 × 2000/500

Vs= 480 V

Vs= 240 × 500/1000

Vs= 120 V

2. Ns/Np= Ip/Is

Is= Np×Ip/Ns

Is= 1000 × 100/2000

Is= 50 A

Is= 2000 × 100/1000

Is= 200 A

Is= 1000 × 100/500

Is= 200 A

Is= 500 × 100/2000

Is= 25 A

Is= 4000 × 100/2000

Is= 200 A

Answer:

t = 23.6 min

Explanation:

First we need to find the mass of air in the room:

m = ρV

where,

m = mass of air in the room = ?

ρ = density of air at room temperature = 1.2041 kg/m³

V = Volume of room = 16 m x 16.5 m x 12.3 m = 3247.2 m³

Therefore,

m = (1.2041 kg/m³)(3247.2 m³)

m = 3909.95 kg

Now, we find the amount of energy consumed to heat the room:

E = m C ΔT

where,

E = Energy consumed = ?

C = Specific Heat of air at room temperature = 1 KJ/kg.⁰C

ΔT = Change in temperature = 21 °C - 13.5 °C = 7.5 °C

Therefore,

E = (3909.95 kg)(1 KJ/kg.°C)(7.5 °C)

E = 29324.62 KJ

Now, the time period can be calculated as:

P = E/t

t = E/P

where,

t = Time needed = ?

P = Power of heater = 20.7 KW

Therefore,

t = 29324.62 KJ/20.7 KW

t = (1416.65 s)(1 min/60 s)

t = 23.6 min

Answer:

Option C - she will speed up because air resistance has reduced and be less than gravity

Explanation:

We are told that Luz is skydiving with terminal velocity and her body parallel to the ground. Now, at this point she will be experiencing a gravitational force acting downwards, and also air resistance as a result of the drag force on her body

Since the downward gravitational force on Luz is constant, she will fall with a net force of;

F_net = F_g - F_d

where;

F_net is the net force on Luz acting downwards

F_g is the gravitational force on Luz

F_d is the drag force on Luz

The drag force on her body is proportional to the surface area of attack.

We are now told that Luz changes her body position to feet first toward the ground. This means that the surface area of attack is reduced because the feet will consume less space than the frontal part of her body. Thus, the drag force will be lesser then before she changed her body position due to reduced air resistance on her body.

Now, from earlier, we saw that;

F_net = F_g - F_d

So, the lesser F_d is, the higher F_net becomes.

Thus, she will speed up because air resistance has reduced and be less than gravity.

Answer:

C

Explanation:

EDGE 2020

Answer:

60 Ω

Explanation:

R(com) = 15 Ω

1/R(com) = 1/R1 + 1/R2 + 1/R3 ..... + 1/Rn

1/15 = 1/20 + 1/R2

1/R2 = 1/15 - 1/20

1/R2 = (4 - 3) / 60

1/R2 = 1/60

R2 = 60 Ω

así, la combinada de resistencia necesaria es 60 Ω

Answer::

   [tex]\lambda = 634 nm[/tex]

  [tex]f = 4.73 *10^{14} \ Hz[/tex]

Explanation:

From the question we are told that

      The  distance of separation is  [tex]d = 0.047 \ mm = 0.047 *10^{-3} \ m[/tex]

       The  distance of the screen is  [tex]D = 6.60 \ m[/tex]

      The  width of the fringe is [tex]y = 8.9 \ cm = 0.089 \ m[/tex]

Generally the width of the width of the fringes is mathematically represented as

          [tex]y = \frac{\lambda * D }{d }[/tex]

=>       [tex]\lambda = \frac{y * d }{D }[/tex]

=>      [tex]\lambda = \frac{ 0.089 * (0.047 *10^{-3}) }{6.60 }[/tex]

=>    [tex]\lambda = 634 *10^{-9}[/tex]

=>  [tex]\lambda = 634 nm[/tex]

Generally the speed of light is mathematically represented as

         [tex]c = f * \lambda[/tex]

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

=>         [tex]f= \frac{ 3.0 *10^{8}}{634 *10^{-9}}[/tex]

=>     [tex]f = 4.73 *10^{14} \ Hz[/tex]

Answer:

testable

Explanation:

high heat can cause browning and or welting

Answer:

A

Explanation:

If it is tested, it will really changed when the plant into low temperature

Answer:

Explanation:

Suppose initially the plane was horizontal and light was reflected back at some angle θ from the normal .

Now the reflecting surface is twisted so that is becomes inclined at angle alpha .

The reflected light will be deviated from its original direction by angle

2 x alpha .

Similarly when the reflecting surface is further twisted so that it becomes inclined at angle beta then again the reflected beam will deviated by angle

2 x beta

Hence angle between these two reflected beam

= 2 beta - 2 alpha

= 2 ( β - α )

So, angular separation between the rays reflected from the two surfaces

= 2 ( β - α ) .

Answer:

Therefore, we need an invert, and a rectifier, along with the transformer to do the job.

Explanation:

A transformer, alone, can not be used to convert a DC voltage to another DC voltage. If we apply a DC voltage to the primary coil of the transformer, it will act as short circuit due to low resistance. It will cause overflow of current through winding, resulting in overheating pf the transformer.

Hence, the transformer only take AC voltage as an input, and converts it to another AC voltage. So, the output voltage of a transformer is also AC voltage.

So, in order to convert a 6 V DC to 1.5 V DC we need an inverter to convert 6 V DC to AC, then a step down transformer to convert it to 1.5 V AC, and finally a rectifier to convert 1.5 V AC to 1.5 V DC.

Therefore, we need an invert, and a rectifier, along with the transformer to do the job.

Answer:

10%

Explanation:

Efficiency = work done / energy used

e = (10 m × 100 N) / (10,000 J)

e = 0.1

The efficiency is 0.1, or 10%.

Answer:

292 nm

Explanation:

The work function of gallium ∅ = 94.25 eV = 6.81 x 10^-19 J

at maximum wavelength, the energy of the photons is equal to its work function

Energy of the electron = hf

but hf = hc/λ

where h is the planck's constant = 6.63 × 10-34 m^2 kg/s

c is the speed of light = 3 x 10^8 m/s

λ is the wavelength that this occurs, which is the maximum wavelength

Equating, we have

hc/λ =  ∅

substituting, we have

(6.63 × 10-34 x 3 x 10^8)/λ = 6.81 x 10^-19

(1.989 x 10^-25)/(6.81 x 10^-19) = λ

λ = 292.07 x 10^-9 = 292 nm

Answer:

Mass of the car is independent of gravity

Explanation:

Here, we want to state the reason why even though we have the acceleration due to gravity absent on the moon, it is still difficult to accelerate a car on a level horizontal level on the moon.

The answer to this is that the mass of the car that we want to accelerate is independent of gravity.

Had it been that gravity has an effect on the mass of the said car, then we might conclude that it will not be difficult to accelerate the car on a horizontal surface on the moon.

But due to the fact that gravity has no effect on the mass of the car to be accelerated, then the problem we have on earth with accelerating the car is the same problem we will have on the moon if we try to accelerate the car on a horizontal level surface.

Answer:

380 kHz

Explanation:

The speed of sound is taken as 1500 m/s

The length of the fetus is 1.6 cm long

The condition is that the wavelength used must be at most 1/4 of the size of the object that is to be imaged.

For this 1.6 cm baby, the wavelength must not exceed

λ = [tex]\frac{1}{4}[/tex] of 1.6 cm = [tex]\frac{1}{4}[/tex] x 1.6 cm = 0.4 cm =

0.4 cm = 0.004 m   this is the wavelength of the required ultrasonic sound.

we know that

v = λf

where v is the speed of a wave

λ is the wavelength of the wave

f is the frequency of the wave

f = v/λ

substituting values, we have

f = 1500/0.004 = 375000 Hz

==> 375000/1000 = 375 kHz ≅ 380 kHz

Answer:

[tex]v_B/v_A=\sqrt{3}[/tex]

Explanation:

Consider the two kinematic equations for velocity and position of an object falling due to the action of gravity:

[tex]v=-g\,t\\ \\position=-\frac{1}{2} g\,t^2[/tex]

Therefore, if we consider [tex]t_A[/tex] the time for the object to reach point A, and [tex]t_B[/tex] the time for it to reach point B, then:

[tex]v_A=-g\,t_A\\v_B=-g\,t_B\\\frac{v_B}{v_A}= \frac{-g\,t_B}{-g\,t_A} =\frac{t_B}{t_A}[/tex]

Let's work in a similar way with the two different positions at those different times, and for which we have some information;

[tex]x_A=-x=-\frac{1}{2}\, g\,t_A^2\\x_B=-3\,x=-\frac{1}{2}\, g\,t_B^2\\ \\\frac{x_B}{x_A} =\frac{t_B^2}{t_A^2} \\\frac{t_B^2}{t_A^2}=\frac{-3\,x}{-x} \\\frac{t_B^2}{t_A^2}=3\\(\frac{t_B}{t_A})^2=3[/tex]

Notice that this quotient is exactly the square of the quotient of velocities we are looking for, therefore:

[tex](\frac{t_B}{t_A})^2=3\\(\frac{v_B}{v_A})^2=3\\ \frac{v_B}{v_A}=\sqrt{3}[/tex]

Answer:

To maintain the same fringe spacing on the screen, the screen-to-slit distance D must be changed to a value 2D that is twotimes D

Answer:

B = 1.33 10⁻⁸ T , the magnetic field must be in the y + direction

Explanation:

In an electromagnetic wave the electric and magnetic fields are in phase

         c = E / B

         B = E / c

let's calculate

          B = 4.00 / 3 10⁸

          B = 1.33 10⁻⁸ T

To determine the direction we use that the electric and magnetic fields and the speed of the wave are perpendicular.

 If the wave advances in the + Z direction and the electric field is in the + x direction, the magnetic field must be in the y + direction

Explanation:

unit is necessary to communicate values of the physical quantity for example can main to someone a particular length without using some sort of unit is impossible because a length cannot be described without a reference used to make sense of the value given

Answer:

2.1×10¹⁸ C

Explanation:

Using,

E = kq/r²...................... Equation 1

Where E = Electric field, q = charge, r = distance, k = coulombs constant.

make q the subject of the equation

q = Er²/k.................. Equation 2

Given: E = 180000 N/C, r = 2.8 cm = 0.028 m

Constant: k = 9×10⁹ Nm²/C².

Substitute these values into equation 2

q = 180000(9×10⁹)/0.028²

q = 2.1×10¹⁸ C

Hence the object charge is 2.1×10¹⁸ C