Which describes the relationship between the frequency, wavelength, and speed of a wave as the wave travels through different media?
As speed changes, wavelength changes and frequency remains constant
As speed changes, frequency changes and wavelength remains constant As speed changes, wavelength and frequency change,
O As speed changes, wavelength and frequency remain constant​

Answers

Answer 1

Answer: A) as speed changes, wavelength changes and frequency remains constant

Explanation: edg test


Related Questions

A nurse asks a doctor about medication for a
patient in a hospital. The doctor accidentally tells
the nurse to give the patient the wrong
medication, and the nurse follows the doctor's
orders. Which type of medical error has occurred?

Answers

Answer:

medication error thats easy

If 500mL glass beaker is filled to the brim with ethyl alcohol at a temperature of 5⁰C, how much less water would overflow under the same condition?​

Answers

Answer:

The change in volume or amount of overflow is 1.79 mL . Hence, 7.56 mL of lesser water would overflow under the same condition.

The nature of light is difficult to grasp because light acts differently in different situations. For example, when light shines through narrow slits, the light behaves as only ________ can. However, when light shines onto a metal and the spray of electrons that comes off is examined, the light behaves as only _________ can.

Answers

Answer:

what do you need us to answer?

Explanation:

Find the final velocity of a 40 kg skateboarder traveling at an initial velocity of 10 m/s that moves up a hill from a height of 0 m to a height of 5 m. Assume gravity is 10 m/s2.
½ m vi2 + m g hi = ½ m vf2 + m g hf

Group of answer choices:
14 m/s

20 m/s

10 m/s

0 m/s

Answers

Answer:

vf = 0

Explanation:

Since the initial height hi = 0, we can rewrite the energy equation as

vf^2 = vi^2 - 2ghf = (10 m/s)^2 - 2(10 m/s^2)(5 m) = 0

Therefore, his final velocity vf is

vf = 0

Part
An object with a charge of 3.53 pc experiences a force of 0.0147 N when it moves at right angles to a magnetic field traveling at 2342 m/s. Find the strength of the
magnetic field

Answers

Answer:

4.05 000 the about id

Explanation:

As an admirer of Thomas Young, you perform a double-slit experiment in his honor. You set your slits 1.13 mm apart and position your screen 3.75 m from the slits. Although Young had to struggle to achieve a monochromatic light beam of sufficient intensity, you simply turn on a laser with a wavelength of 647 nm . How far on the screen are the first bright fringe and the second dark fringe from the central bright fringe

Answers

Answer:

Explanation:

slit separation d = 1.13 x 10⁻³ m

screen distance D = 3.75 m

wavelength of light λ = 647 x 10⁻⁹ m

Distance of first bright fringe = fringe width = λ D / d

λ D / d  = 647 x 10⁻⁹ x 3.75 m / 1.13 x 10⁻³ m

= 2.147 x 10⁻³ m

= 2.147 mm .

Distance of first bright fringe = 2.147 mm .

Distance of second  dark  fringe = 1.5 x fringe width

= 1.5 x 2.147 mm .

= 3.22 mm .

What happens when two oceanic plates collide?

Answers

Answer:

The denser plate is subducted underneath the less dense plate

Explanation:

When two oceanic plates collide one oceanic plate is eventually subducted under the other. ... When two oceanic plates collide, the denser plate is subducted and some material rises upward and forms an ISLAND.

Answer:

C (I think)

Explanation:

Because when two oceanic plates converge, the denser plate will end up sinking below/under the less dense plate. Forms a subduction zone.

Question below in photo!! Please answer! Will mark BRAINLIEST! ⬇⬇⬇⬇⬇⬇⬇
----------------------------------------------------------------------------------------------
Chose the correct answer:
-Increases
-Decreases
-Stays the same

Answers

Answer:

Decreases seems most reasonable to me but up to you.

The largest flowers in the world are the Rafflesia Arnoldii, found in Malaysia. A single flower is almost a meter across and has a mass up to 11.0 kg. Suppose you cut off a single flower and drag it along the flat ground. If the coefficient of kinetic friction between the flower and the ground is 0.39, what is the magnitude of the frictional force that must be overcome?

Answers

The magnitude of the frictional force that must be overcome is 42.04 N.

What is the magnitude of the frictional force?

The magnitude of the frictional force that must be overcome is calculated by applying Newton's second law of motion as follows;

Mathematically, the formula for the frictional force is given as;

F = μmg

where;

μ is the coefficient of frictionm is the mass of the flowerg is acceleration due to gravity

The magnitude of the frictional force that must be overcome is calculated as;

F = 0.39 x 11 kg  x  9.8 m/s²

F = 42.04 N

Learn more about frictional force here: https://brainly.com/question/4618599

#SPJ1

A force of 20 Newtons moves a box 2.0 meters and does 40 N*m of work. How many Joules is this?

Answers

1 N*m = 1 Joule

40 N*m = 40 joules

Exercise 24.28
For the capacitor network shown in (Figure 1), the potential difference across ab is 48 V.
Part A
Find the total charge stored in this network.
Express your answer with the appropriate units.
Q = ___ ____
Part B
Find the charge on the 150nF capacitor.
Express your answer with the appropriate units.
Q₁ = 7.2uC
Part C
Find the charge on the120nF capacitor.
Express your answer with the appropriate units.
Q₂ = 5.76 uC
Part D
Find the total energy stored in the network.
Express your answer with the appropriate units.
U = ____ ____
Part E
Find the energy stored in the 150nF capacitor.
Express your answer with the appropriate units.
U₁ = ______
Part F
Find the energy stored in the 120nF capacitor.
Express your answer with the appropriate units.
U₂= _____
Part G
Find the potential difference across the 150nF capacitor.
Express your answer with the appropriate units.
V₁= ____
Part H
Find the potential difference across the 150nF capacitor.
Express your answer with the appropriate units.
V₂ = ____

Answers

The evaluation of the capacitor (in series) network is as follows;

Part A

Q = 3.2 μC

Part B

Q₁ = 3.2 μC

Part C

Q₂ = 3.2 μC

Part D

U = 76.8 μJ

Part E

U₁ = 34 2/15 μJ

Part F

U₂ = 53 1/3 μJ

Part G

V₁ = 21 1/3 V

Part H

V₂ = 26 2/3 V

What is a capacitor?

A capacitor consists of pairs of conductors separated by insulators. Capacitors are used to store electric charge.

The specified parameters are;

The voltage across ab = 48 V

The capacitance of the first capacitor, C₁ = 150 nF

Capacitance of the second capacitor, C₂ = 120 nF

Part A

The total charge in a capacitor network can be found as follows;

[tex]C_{eq} = \left(\dfrac{1}{150} + \dfrac{1}{120} \right)^{-1} nF = \left(\dfrac{3}{200} \right)^{-1}nF[/tex]

[tex]C_{eq} =\left(\dfrac{3}{200} \right)^{-1}nF=66\frac{2}{3} \, nF[/tex]

[tex]Q_{eq} = C_{eq}\times V_{ab}[/tex]

Therefore;

[tex]Q_{eq}[/tex] = 66 2/3 nF × 48 V = 3,200 × 10⁻⁹ C = 3.2 μC

The total charge in the circuit is 3.2 μC

Part B

The charge in the 150 nF capacitor is obtained from the formula for the charge in a capacitor; Q = C × V as follows;

Q = C₁V₁ = C₂V₂

The charge in the capacitors, C₁ and C₂ are the same as the total charge of 3.2 μC

The charge, Q₁ on the 150 nF capacitor, C₁ is therefore, 3.2 nC

Q₁ = 3.2 nC

Part C

The capacitors, C₁ and C₂ are in series, therefore, the charge in each capacitor is equivalent to the charge in the circuit, which is 3.2 μC.

Therefore, the charge, Q₂, in the 120 nF capacitor, C₂ is 3.2 μC

Q₂ = 3.2 μF

Part D

The total energy stored in the network can be obtained using the formula;

U = (1/2)·C·V²

Where;

U = The energy in the capacitor

C = The equivalent capacitance of the network = 66 2/3 nF

V = The voltage

Therefore;

[tex]U = \dfrac{1}{2} \times C_{eq}\times V^2[/tex]

[tex]U = \dfrac{1}{2} \times 66\frac{2}{3} \times 10^{-9}\times 48^2 = 76.8[/tex]

The total energy in the circuit, U = 76.8 μJ

Part E

The energy stored in the 150 nF capacitor is found as follows;

[tex]Q_{eq}[/tex] = Q₁ = C₁ × V₁

V₁ = [tex]Q_{eq}[/tex] ÷ C₁

Therefore;

V₁ = 3.2 μC ÷ 150 nF = [tex]21\frac{1}{3}[/tex] V

U₁ = 0.5×C₁×V₁²

U₁ = 0.5 × 150×10⁻⁹ × [tex]\left(21\frac{1}{3} \right)^2[/tex] = 34[tex]\frac{2}{15}[/tex] μJ

Part F

The energy stored in the 120 nF capacitor, U₂, can be found as follows;

V₂ = 3.2 μC ÷ 120 nF = [tex]26\frac{2}{3}[/tex] V

U₂ = 0.5 × 150 nF × [tex]\left(26\frac{2}{3} \, V\right)^2[/tex] = [tex]53\frac{1}{3}\, \mathrm{ \mu J}[/tex]

The energy in the 120 nF capacitor is; U₂ = 53 1/3 μJ

Part G;

The potential difference across the 150 nF, obtained in Part E, is 21 1/3 V

V₁ = 21 1/3 V

Part H

The potential difference across the 120 nF, obtained in part F, is 26 2/3 V

V₂ = 26 2/3 V

Learn more about capacitors networks here: https://brainly.com/question/9525710

#SPJ1

When, how and where are questions asked during critical inquiry?*
1 p
True
False

Answers

Answer:

true

Explanation:

POSSIBLE POINTS: 1
This is another example of a lever.



Identify each part, A, B and C, and then classify the lever as 1st, 2nd, or 3rd class.

Responses

A. fulcrum, B. load, C. effort. 2nd class
A. fulcrum, B. load, C. effort. 2nd class

A. load, B. fulcrum, C. effort. 1st class
A. load, B. fulcrum, C. effort. 1st class

A. load, B. fulcrum, C. effort. 3rd class
A. load, B. fulcrum, C. effort. 3rd class

A. effort, B. fulcrum, C. load. 1st class

Answers

In the given image A. load, B. fulcrum, C. effort. 1st class. The correct option is B.

What is fulcrum?

The pivotal point of the beam is known as the fulcrum. A load is applied at the other end of a lever when an effort is exerted to one end of the lever. A mass will be raised as a result.

The fulcrum of first-class levers is in the centre. Levers of the second class have the load in the centre.

This indicates that a heavy load can be moved with only moderate effort. - Levers of the third class exert middle-of-the-road force.

The illustration shows a class 1 lever with a fulcrum in the middle and load and effort located at the other two ends.

Thus, the correct option is B.

For more details regarding fulcrum, visit:

https://brainly.com/question/3445140

#SPJ1

Which two statements correctly describe transmutation? O A. The parent and daughter elements are different. B. The atomic masses of the parent and daughter elements are the same. c. Neither the number of atoms nor the number of nucleons is conserved. D. The number of nucleons is conserved.​

Answers

Answer:

A. and D.

Explanation:

Statements A and D best correctly describe transmutation. The parent and daughter elements are different, and the number of nucleons is conserved.​

What is transmutation?

Transmutation is the process of converting one chemical element to another. Transmutation is any process that alters the number of protons or neutrons in an atom's nucleus.

The  statements correctly describe transmutation are;

A. The parent and daughter elements are different

D. The number of nucleons is conserved.​

Hence, statements A and D best correctly describe transmutation.

To learn more about the transmutation, refer to the link;

https://brainly.com/question/11545568

#SPJ2

Suppose you observe a star orbiting the galactic center at a speed of 1400 km/s in a circular orbit with a radius of 26 light-days. Calculate the mass of the object that the star is orbiting. Express your answer in solar masses to two significant figures.

Answers

Answer:

M = 9.9 x 10⁶ Solar masses

Explanation:

Here the centripetal force is given by the gravitational force between star and the object:

[tex]Gravitational\ Force = Centripetal\ Force \\\frac{mv^2}{r} = \frac{GmM}{r^2}\\\\M = \frac{v^2r}{G}[/tex]

where,

M = Mass of Object = ?

v = orbital speed of star = 1400 km/s = 1400000 m/s

G = Universal Gravittaional Constant = 6.67 x 10⁻¹¹ N.m²/kg²

r = distance between star and object = (26 light-days)(2.59 x 10¹³ m/1 light-day) = 6.735 x 10¹⁴ m

Therefore,

[tex]M = \frac{(1400000\ m/s)^2(6.735\ x\ 10^{14}\ m)}{6.67\ x \ 10^{-11}\ N.m^2/kg^2}[/tex]

M = (1.97 x 10³⁷  kg)(1 solar mass/ 1.989 x 10³⁰ kg)

M = 9.9 x 10⁶ Solar masses

A uniform beam is 2m long, has a mass 100 kg, and it is supported at its center by a triangular support. the beam is balanced. Mass m1 is 25 kg mass m2 is 10 kg. a. If the distance d is 0.25 m what will the value of mass mx be such that the beam is balanced? b. If you were to remove mass mx and moved the support instead. What will that distance L be such that the beam remains balanced, see figure below

Answers

Answer                

Explanation:

                             

Which of the following does NOT take place at the mission control center?
Doing contracting work for government agencies of private businesses
International Space Center
Sending signals to the space craft
Planning the details of the mission

Answers

MISSION CONTROL CENTER

Doing contracting work for government agencies of private businesses

The mission control center is a facility that is responsible for controlling and coordinating the operations of a spacecraft during a mission. It is typically run by NASA or another space agency and is used to monitor and communicate with spacecraft, as well as to plan and execute mission objectives. The mission control center is not typically involved in contracting work for government agencies or private businesses.

Hope This Helps You!

A 350 gram mass is tied to a string and spin in a horizontal circle with a radius of 11.0cm.The speed of the mass is held constant and the period of rotation is 0.6seconds. a)What is the angular speed of this mass? b)What is the linear speed of this mass?​

Answers

Explanation:

a) The angular speed omega is given defined as

omega = #rev/period = 1 rev/(0.6 s) = 1.7 rev/s

= (1.7 rev/s)×(2pi/rev) = 10.5 rad/s

b) v = (omega)×r

= (10.5 rad/s)(0.110 m)

= 1.16 m/s

The average speed of an object during a specified period of time is a. Always equal to the magnitude of the average velocity for the same period of time. b. Never equal to the magnitude of the average velocity for the same period of time. c. Equal to the magnitude of the average velocity for the same time period if the direction of motion does not change. d. Sometimes equal to the magnitude of the average velocity for the same t

Answers

Answer:

c. Equal to the magnitude of the average velocity for the same time period if the direction of motion does not change.

Explanation:

Speed can be defined as distance covered per unit time. Speed is a scalar quantity and as such it has magnitude but no direction.

Mathematically, speed is given by the equation;

[tex]Speed = \frac{distance}{time}[/tex]

Motion can be defined as a change in the location (position) of a physical object or body with respect to a reference point.

This ultimately implies that, motion would occur as a result of a change in location (position) of an object with respect to a reference point or frame of reference i.e where it was standing before the effect of an external force.

The average speed of an object during a specified period of time is equal to the magnitude of the average velocity traveled or covered in the same time period and in a straight line i.e if the direction of motion does not change.

OMGGG PLSSS Which of the following means that a lens causes light rays to spread apart?
A. +di
B. -di
C. -f
D. +f

Answers

Answer: -f

Explanation:

Answer: -f

Explanation:

just took the test and got it right

How are work and power different

Answers

Work is defined as the process of energy transfer to the motion of an object through the application of force. Power is defined as the amount of energy transferred in unit time.

Two charged parallel plates are 0.25 meters away from each other. The field between the plates is 600 What is
the electric potential difference?
AV =

Answers

Answer:150

Explanation:

Identify the type of particle that would be given off by each of the following nuclear reactions:
What isotope is produced when plutonium-239 (Pu-239) undergoes alpha decay?
A. Lead-210
B. Thorium-234
C. Uranium-235

Answers

Answer:

C po ang sa got pa braenlest

Answer:

C. Uranium-235

Explanation:

I just took the test.

One of the largest organ pipes is in the auditorium organ in the convention hall in
Atlantic City, New Jersey. The pipe is 38.6 ft long and produces a sound with a
wavelength of about 10.6 m. If the speed of sound in air is 346 m/s, what is the
frequency of this sound?

Answers

Among electromagnetic waves, UV rays are most dangerous because exposure to these radiation cause serious problems in living organism. Thus the frequency of sound wave is 0.135 s⁻¹.

What is electromagnetic wave?

Electromagnetic wave is a wave which contain two component one is electric component and other is magnetic component. The electric and magnetic component are perpendicular to each other. There are so many wave that comes under electromagnetic wave like infrared wave , radio wave, light wave.

There is a relation between frequency of wave, and wavelength of wave

Mathematically,

speed=distance/time

where,  

ν=frequency of light

c is speed of light that is 3×10⁸m/s

λ is the wavelength of light=4.5x10² nm= 10.6 m

Substituting all the values

346 m/s =11.76m÷ t

t=0.033= 0.135 s⁻¹

Thus the frequency of sound wave is 0.135 s⁻¹.

To know more about electromagnetic wave, here:

https://brainly.com/question/12289372

#SPJ1

Find force if mass is 60 kg and acceleration is 2.1 m/sec2

Answers

F = 126 N

Explanation:

F = ma

= (60 kg)(2.1 m/s^2)

= 126 N

Answer:

[tex]\boxed {\boxed {\sf 126 \ Newtons}}[/tex]

Explanation:

Force is the push or pull on an object. It is the product of mass and acceleration so the formula is:

[tex]F= m \times a[/tex]

The mass is 60 kilograms and the acceleration is 2.1 meters per square second.

m= 60 kg a= 2.1 m/s²

Substitute the values into the formula.

[tex]F= 60 \ kg *2.1 \ m/s^2[/tex]

Multiply.

[tex]F= 126 \ kg*m/s^2[/tex]

1 kilogram meter per square second (1 kg *m/s²) is equal to 1 Newton (N)Our answer of 126 kg*m/s² is equal to 126 N

[tex]F= 126 \ N[/tex]

The force is 126 Newtons.

Rank the images showing the highest electric potential 1 energy to the lowest electric potential energy 4.

Answers

Answer:

3rd image, 2nd image, 1st image, 4th image

Explanation:

Not an easy question, tricky one

Electric potential energy is proportional to the magnitude of the charges (the higher the charges, the stronger the Electric potential energy(EPE)) and inversely proportional to the distance between the charges(the longer the distance, the smaller the EPE).  U = kQq/r

EPE is positive in this case due to unlike charges.

Between distance and magnitude of the charges, magnitude of charges play a more significant effect than distance (due to Qq , both the magnitude of Q and q affect the EPE)

Hence. zoom in on the magnitude first.

3rd image has the largest + and -, hence greatest magnitude of charges, therefore highest EPE.

Between 1st and 2nd images, charges have the same magnitude, distance now comes to play. Distance between the charges is smaller for image 2 and the charges experience greater EPE. 1st image, the charges are further, hence smaller EPE.

For the fourth image, the magnitude of the charges is the smallest, hence smallest EPE.

how is the energy of boiling water in an electric kettle a different energy from electric fan changing to kinetic energy

Answers

The energy of boiling water in an electric kettle is thermal energy, which is created by a transfer of electrical energy from the kettle to the water.

What is Energy?

Energy is a fundamental physical quantity that is a property of objects and their environment. It is the ability to do work and is often associated with the motion of objects. In physics, energy is defined as the capacity to do work and is measured in joules. It can take many forms such as thermal, kinetic, electrical, mechanical, and chemical.

Electric fan changing to kinetic energy is the conversion of electrical energy from the fan motor into kinetic energy, which is the energy of motion.

Kinetic energy is basically the energy of motion. It is the energy an object has due to its motion. It is defined as the work which is needed to accelerate a body of a given mass from rest to its current velocity.

To know more about energy,

https://brainly.com/question/2003548

#SPJ1

Explain why a solid has a definite shape
and volume.
6. How does the arrangement of atoms in most
solids differ from the arrangement of atoms in
a liquid?

Answers

According to the given statement Atoms in solids vibrate motionless, whereas atoms in fluid move.

Where are atoms found?

Everything, that's correct. Matter includes all liquids, solids, sand, plants, animals, and clouds. The building components of matter are called atoms. All stuff is made up of numerous atoms, like how this house is built of many bricks. Because they are not living entities, atoms don't require food, water, or oxygen, and they can't procreate.

Can you kill an atom?

The law of energy conservation states that matter cannot be generated or destroyed. As a result, an atom could be destroyed or divided into smaller particles. The electron, proton, the neutron are the three fundamental particles that make up an atom.

To know more about Atom visit:

https://brainly.com/question/12231872

#SPJ1

who is known as the father of India​

Answers

Answer:

the answer is

Mahatma Gandhi

Answer:

Mahatma Gandhi

hope it helps.

convert 22.0m/s² to km/min²​

Answers

22.0m/s² is equal to 78.98 km/min²​. Since 1 m/s² = 3.59 km/m². If we multiply 22 by this number, we get the accurate answer, according to the conversion table.

What is the acceleration unit in the SI?

Acceleration is measured in meters per second2 (m/s2). Newton's Second Law, which states that "The acceleration of an object is exactly proportional to the net force acting on it and inversely proportionate to its mass," connects force (F), mass (m), and acceleration (g).

The SI unit is what?

The Système International unit, or SI unit, is an acronym for the French phrase for system international. The metric system that serves as the industry standard for measurements is called the International System of Units (SI). In the advancement of science and technology, SI units are essential.

To learn more about acceleration visit:

brainly.com/question/12550364

#SPJ1

Other Questions
A compound with EF CH2 was found to have a Molar mass of 84g. What is the MF of the compound? PLZ HELPPPPPPPPPPPPP MEEEEEEEEEEEEEE FASTTTTTTTTTTT BECAUSE I HAVE TO MUCH OTHER WORK TO DO. Which isotope, when bombarded with nitrogen-15, yields the artificial isotope dubnium-260 plus 4 neutrons Examine the given run chart or control chart and determine whether the process is within statistical control. If it is not, identify which of the three out-of-statistical-control criteria apply.A. Process mean is not within statistical control. One of the points lies above the upper control limit.B. Process mean is not within statistical control. There are points above and below the control limits.C. Process mean is not within statistical control. There is an upward trend which is indicating an increase in variation.D. Process mean is within statistical control. The solid below is made of twelve identical rectangular prisms. The overall dimensions of the composite solid are 36 inches (in.) by 36 inches by 24 inches. What is the volume, in cubic inches, of a single prism?Whoever answers correctly will get Brainliest. Find an equation of the circle that has center -(-5,6) and passes through (-1,1). 6. Find the greatest odd integer value of x that satiste the inequality 3x < -105. a family buys a new home for $212,500 and pays a 20% down payment ($42,500). if the mortgage is for 15 years at 5.75% interest which is their monthly house payment What is the equation for the linear relationship in slope intercept form? taylor swift music team helped take down tracks from her album 1989 that were What is an advantage of a health maintenance organization (HMO)? Plz help me plz help Gimli has been working hard in a desert environment, but has neglected to drink any water to replace the 2L of fluid lost via sweat and respiratory losses (think 600 ml lost from the blood volume). He had to stop working because he felt weak, but still feels poorly after a few minutes of rest.Gimli, is the cardiac contractility:________a. increasedb. decreasedc. not significantly changed What did Nat Turner's Rebellion consist of? A school is selling cookies as a fundraiser. Each box contains 10 cookies. Each student can sell 17 boxes of cookies. How many cookies can 11 students sell An engineer has recently purchased a new piece of equipment to use in analyzing geological formations. The equipment has no maintenance costs the first year due to a one year's free maintenance warranty. In the second year, it is expected to cost $20 to maintain the equipment and in subsequent years the cost of maintenance will increase by $20 per year (i.e. maintenance cost is $40 in year three, $60 in year four, and so on). Approximately what amount must be set aside now at 9% interest to pay the cost of maintaining the equipment over the first six years of ownership 5 feet x 3 feet x 2 and 1/4 7.) A 72 kg skier is beginning to ski down a slope starting 90 meters high. There is an issue, the skier didnot see a curb in the slope and did not realize they were going to hit a wall at the bottom of the slope. Itwas observed by a nearby instrument that when the skier collided with the wall of snow there was 64 Jof sound energy given off. The rest of the kinetic energy was converted to heat energy, what was theamount of kinetic energy converting to heat from the collision? Select all expressions that are equivalent to 3x - 2 (x - 4) - 1 Q6.4 Points: 2 Suppose that Angela wants to use her sample to create a 68% confidence interval for the true population median of boba weight per drink and she knows that the population SD is 2 grams. What is the minimum sample size she needs to create a confidence interval that has a width of 0.4 grams?