topic 4 homework questions

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4th grade (Eureka Math/EngageNY)

Unit 1: module 1: place value, rounding, and algorithms for addition and subtraction, unit 2: module 2: unit conversions and problem solving with metric measurement, unit 3: module 3: multi-digit multiplication and division, unit 4: module 4: angle measure and plane figures, unit 5: module 5: fraction equivalence, ordering, and operations, unit 6: module 6: decimal fractions, unit 7: module 7: exploring measurement with multiplication.

Revision notes for IB Physics

Topic 4: waves.

See the guide for this topic.

4.1 – Oscillations

Simple harmonic oscillations.

Oscillations are periodic motions which center around an equilibrium position.

Simple harmonic motion (SHM) is a special type of oscillation. For example:

• The simple pendulum
• The vibration of strings in a violin
• The spring-mass system, where the mass is initially displaced to produce a periodic motion around the equilibrium position

An object undergoes SHM if it experiences a force which is proportional and opposite of the displacement from its equilibrium position.

for a pendulum

for a spring-mass system

Time period, frequency, amplitude, displacement and phase difference

Conditions for simple harmonic motion

• When the body is displaced from equilibrium, there must exist a restoring force (a force that wants to pull the body back to equilibrium).
• The magnitude of the restoring force must be proportional to the displacement of the body and acts towards the equilibrium.

4.2 – Travelling waves

Travelling waves.

A travelling wave is a continuous disturbance in a medium characterized by repeating oscillations. For example:

• A rope that is flicked up and down continuously creates a repeating disturbance similar to the shape of a sine/cosine wave.

Energy is transferred by waves.

Matter is not transferred by waves.

The direction of a wave is defined by the direction of the energy transfer.

Wavelength, frequency, period and wave speed

Wavelength, frequency, and period follow the same rules of SHM.

Wave speed can be calculated by the following equation

Transverse and longitudinal waves

The nature of electromagnetic waves.

All EM waves travel in vacuum at the same speed of 3*10^8m/s.

EM waves are transverse waves.

The nature of sound waves

The speed of sound in 20 degrees Celsius dry air is approximately 343.2m/s.

Sound waves are longitudinal waves.

4.3 – Wave characteristics

Wavefronts and rays.

Wavefronts:

• Lines joining points which vibrate in phase.
• Can be straight lines or curves.
• The distance between successive wavefronts is the wavelength of the wave.
• Lines which indicate the direction of wave propagation.
• Rays are perpendicular to wavefronts.

Amplitude and intensity

The amplitude and intensity of a wave depends on its energy.

The intensity of a wave is proportional to the square of its amplitude (I∝A^2).

See previous section with the same title.

Superposition

The principle of superposition states that the net displacement of the underlying medium for a wave is equal to the sum of the individual wave displacements.

The left shows constructive interference (superposition) where the two waves add up (e.g. 1+1=2). The right shows deconstructive interference (superposition) where the two waves cancel each other (e.g. 1+(-1)=0).

Polarization

Light is a transverse wave (polarization only occur to transverse waves).

The polarization of light refers to the orientation of the oscillation in the underlying electric field.

Light is plane polarized if the electric field oscillates in one plane.

Left shows unpolarized light and right shows polarized light.

Polarization by reflection

When light is transmitted across a boundary between two mediums with different refractive indexes, part of the light is reflected and the remaining part is refracted (for further explanation, see section 4.4).

The light reflected is partially polarized, meaning that it is a mixture of polarized light and unpolarized light.

The extent to which the reflected light is polarized depends on the angle of incidence and the refractive index of the two mediums.

The angle of incidence at which the reflected light is totally polarized is called the Brewster’s angle (ϕ) given by the equation

where n1 and n2 are the refractive indexes for their respective mediums

When the angle of incidence is equal to Brewster’s angle, the reflected ray is totally polarized and the reflected ray is perpendicular to the refracted ray.

Polarizers and Analyzers

• A polarizer is a sheet of material which polarizes light.
• When unpolarized light passes through a polarizer, its intensity is reduced by 50%.
• When polarized light passes through a polarizer, its intensity will be reduced by a factor dependent on the orientation of the polarizer. This property allows us to deduce the polarization of light by using a polarizer.
• A polarizer used for this purpose is called an analyzer.

Malus’ Law relates the incident intensity and transmitted intensity of light passing through a polarizer and an analyzer.

where I is the transmitted intensity, I0 is the initial light intensity upon the analyzer, θ is the angle between the transmission axis and the analyzer.

When light passes through an optically active substance, the plane of polarization rotates.

4.4 – Wave behaviour

Reflection and refraction.

Angle of incidence = Angle of reflection

Reflection of waves from a fixed end is inverted.

Reflection of waves from a free end is not inverted.

Refraction is the change in direction of a wave when it transmits from one medium to another.

The angle of incidence and the angle of refraction can be determined by Snell’s law given by the following formula

Fast-to-slow: towards normal; slow-to-fast: away from normal

In addition, the refractive index n1 and n2 are related by the following equation

where v1 and v2 are the speed of the waves in their respective mediums and λ1 and λ2 are the wavelength of the waves of their respective mediums

Snell’s law, critical angle and total internal reflection

See previous section (Reflection and refraction) for Snell’s law.

Diffraction through a single-slit and around objects

• Diffraction through a single-slit

Single-slit equations are not required for the standard level course.

• Diffraction around objects

Interference patterns

Maximums form at constructive interference (the maximum is shown by 1-2) and minimums form at deconstructive interference (the first minimum is shown by 3-4).

Double-slit interference

Like single-slit diffraction, double-slit diffraction occurs via the same methods of interference and has a similar diffraction pattern.

Path difference

4.5 – Standing waves

The nature of standing waves.

Standing waves (stationary) waves result from the superposition of two opposite waves which are otherwise identical.

Energy is not transferred by standing waves.

A wave hits a wall and is reflected identically opposite.

The black wave shows the wave created by the superposition of the blue and green waves.

Boundary conditions

Air particles can oscillate and create standing waves in pipes with open or closed ends.

Antinodes are positioned at open ends and nodes are positioned at closed ends.

Standing waves on a string is equivalent to that in a pipe which is closed on both ends (nodes-node).

The following table summarizes the behavior of standing waves in pipes and strings:

Nodes and antinodes

Positions along the wave which are fixed are called nodes (minimum) and those with the largest displacement are called antinodes (maximum).

For standing waves, the distance between adjacent nodes = the distance between adjacent antinodes = λ/2.

Difference between standing waves and travelling waves

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101 Exciting 4th Grade Writing Prompts for 2023 (Free Printable!)

Use them for journal writing, essay topics, and more!

Fourth grade is a time for students to continue to hone their writing chops as they put to use the skills they’ve learned and gain confidence in their abilities. We’ve collected this list of fourth grade writing prompts—including opinion, persuasive, informational, and narrative—to spur your students’ imaginations and get them writing!

You can get 50 of these fourth grade writing prompts in a free PowerPoint slideshow bundle! They make it easy to share these writing ideas with your students.  Grab your free PowerPoint bundle by submitting your email here .

• Persuasive and Opinion Writing Prompts
• Descriptive and Expository Writing Prompts
• Narrative and Personal Writing Prompts
• Creative Writing Prompts
• Current Events Writing Prompts

Persuasive and Opinion 4th Grade Writing Prompts

Would you rather be good at sports or good in school? Why?

Would you rather have lots of money or lots of friends? Why?

What is your favorite subject in school? Why?

Are fourth graders ready to stay home alone? Why or why not?

Name two characters from different books that you think might be good friends. Why?

Which is more important for success, skill or luck?

Should kids be paid an allowance to do chores around the house? Why or why not?

Why are classroom rules important?

If you had a time machine, what era of history would you visit?

Why is math important?

Why is science important?

Should fourth graders have cell phones? Why or why not?

If you could open a store, what type of store would it be and why?

Which would you rather read: a scary story that gives you goosebumps or a funny story that cracks you up? Why?

What is the hardest thing about being a fourth grader?

If I were the ruler of the world, the first law I would pass would be … because …

If you found a backpack filled with dollar bills, what would you do?

Is it ever OK to tell secrets? Why or why not?

What animal makes the best pet? Why?

Is it better to spend an hour a day reading or an hour a day exercising? Why?

Descriptive and Expository 4th Grade Writing Prompts

If you had a YouTube channel, what would you talk about?

What’s the best book you’ve read recently? What was it all about?

If you won a million dollars, how would you spend the money?

Describe what you think of as perfect weather.

Describe how to build a birdhouse step by step.

Write five rules for staying organized.

What is the worst book you ever read?

Describe the physical appearance of someone in your family in detail.

Imagine you are in a hot-air balloon above your house. Describe everything you can see.

Describe how to play your favorite board game.

There’s an old saying: “The squeaky wheel gets the grease.” What do you think this saying means?

Describe your perfect day.

One of your little cousins is very nervous about starting kindergarten. What would you tell them to make them feel better?

Imagine you are an adult and describe your dream job.

Explain your morning routine in detail, from waking up to arriving at school.

Describe the perfect meal, including what you’d eat and where you’d dine.

Share what you do on a typical non-school day.

Explain the right way to do one of your household chores, like making your bed or cleaning your room.

Describe your favorite room at home in detail.

How do you prepare for a big test? Describe the ways you study or practice.

Narrative and Personal 4th Grade Writing Prompts

Share one of the stories your family has told you about when you were a baby.

What is the funniest thing that has ever happened to you?

Write about an adult you look up to.

What’s the nicest thing anybody has ever done for you?

If you could change one thing about yourself, what would it be?

Write about a time you felt like quitting but didn’t. How did you keep yourself going?

Do you like nonfiction books or fiction books better? Why?

What makes your family unique?

What would you say is your greatest strength? Greatest weakness?

Are you a patient person? Why or why not?

What is something you’ve never done that you would like to try?

What is the weirdest thing that has ever happened to you?

Write about a time you tried something new and how you felt before, during, and after.

What is your earliest memory?

What’s your favorite holiday? What makes it so special?

Write about a time when you felt proud of yourself.

Tell the story of your favorite field trip of all time.

If you could relive any day in your life, what would it be? Would you want it to be the same or different?

What holiday is important to your family? Describe how you celebrate it together.

What’s the best gift you’ve ever gotten? How did it make you feel?

Creative 4th Grade Writing Prompts

If you met an alien, what three questions would you ask them?

Pretend you drank a magic potion that made you as tiny as an ant. Where would you go and what would you do?

Pretend you ate a magic pill that made you as tall as a redwood tree. Where would you go and what would you do?

Write a story that includes these five words: keys, spaghetti, uncle, jellyfish, spaceship.

What would the world be like if dinosaurs still existed?

If you could invent something new the world really needs, what would it be? How would it work?

Retell a classic story, making the villain the hero instead.

Imagine that one day you woke up and found everyone in the world could no longer talk. What would happen next?

Write a new chapter of your favorite book, with yourself as a new character.

Imagine you woke up one morning with a superpower, like invisibility or the ability to fly. Describe your experiences learning how to use that power.

Use these words to start a story: “When I opened the box that came in the mail, I never expected to find …”

Describe a world where it rains fruit juice and snows M&Ms.

Come up with the most ridiculous excuse possible for why you are unable to turn in your homework today.

Describe a world where all the adults are robots, but kids are still human kids.

Imagine a conversation between yourself and a talking animal.

Describe the kind of creature you’d create if you were a mad scientist. Would it be scary and mean? Nice and friendly?

Invent a new kind of candy. Give it a name, and write a commercial jingle for it.

Write about a day where kids are in charge instead of grown-ups.

Imagine you’re lost in a haunted wood, and tell the story of your escape.

Tell a story that ends with these words: “… and that’s how we all learned to fly.”

Describe a night in the life of the tooth fairy.

Current Events 4th Grade Writing Prompts

If you made a time capsule for this year, what would you put in it?

Describe something that you saw in the news recently and how it made you feel.

Tell about an event that happened recently at your school or in your town.

What do you think is one of the world’s biggest problems right now, and how would you solve it?

Read a news story about something happening in another country and summarize it.

Write a news article about something important that happened to you this week.

Create a poem about something in the local news right now.

Write a letter to the editor about a current issue, explaining your opinion.

Find a “good news” story, and share why it makes you happy.

What living famous person do you most admire and why?

What do you think kids today can do about climate change and global warming?

Learn about an endangered animal, and describe what we can do to help it.

What does the word “racism” mean to you?

What is one thing you would do to make your school or town a better place?

Choose an upcoming sports event, and explain who you think will win.

Describe a current fashion trend or something that’s very popular in your school right now, and how you feel about it.

What can we do to help people with different opinions get along with one another better?

Interview a grown-up you know, and write a news article about them.

What do you think is the best new song right now? The worst? Why?

Describe an event that’s happening in the world right now that you don’t understand. What questions would you ask a grown-up about it?

How do you use writing prompts with your students? Come share your ideas and ask for advice in the We Are Teachers HELPLINE group on Facebook .

Also check out 57 awesome 4th grade books you’ll want to share with students ..

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75 Creative Fifth Grade Writing Prompts (Free Slides!)

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Topic 4 Acc Living Environment: Reproduc...

8th - 10th grade.

Topic 4 Acc Living Environment: Reproduction & Development

40 questions

Introducing new   Paper mode

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• 1. Multiple Choice Edit 1 minute 1 pt How much DNA do you receive from one parent in asexual reproduction? 25% 50% 75% 100%
• 2. Multiple Choice Edit 1 minute 1 pt How much DNA do you receive from one parent in sexual reproduciton 25% 50% 75% 100%
• 3. Multiple Choice Edit 1 minute 1 pt What is a disadvantage to asexual reproduction? It produces more offspring It produces fewer offspring They are all the same and do not have diversity They are all different and have diversity
• 4. Multiple Choice Edit 1 minute 1 pt Which of the following is an advantage of sexual reproduction for a species. It produces more offspring Offspring can better adapt to changing environments because they are diverse Off spring are more likely to die because they are all 100% identical to their parent. It produces fewer offspring
• 5. Multiple Choice Edit 1 minute 1 pt The main purpose of mitosis is for growth only.  tissue repair only.  growth and tissue repair.  neither growth nor tissue repair
• 7. Multiple Choice Edit 3 minutes 1 pt Meiosis produces ___________ while mitosis produces __________. Sex cells, body cells Body cells, sex cells
• 8. Multiple Choice Edit 3 minutes 1 pt A guinea pig cell has 64 chromosomes.  After mitosis, each daughter contains ___ chromosomes. 128 64 32 16
• 10. Multiple Choice Edit 1 minute 1 pt Genetic variation during sexual reproduction is due to sorting of genes during meiosis sorting of genes during mitosis pairing of genes during differentiation pairing of genes during mitosis
• 13. Multiple Choice Edit 1 minute 1 pt During sexual reproduction, 2 cells fuse together.  If two cells are fusing, how does the number of chromosomes remain the same from generation to generation?  mitosis and meiosis differentiation and mitosis meiosis and fertilization homeostasis and mitosis
• 14. Multiple Choice Edit 1 minute 1 pt In order for a mutation to be passed on to offspring, the mutation must occur in gametes (sex cells, such as sperm and egg) blood cells body cells somatic cells
• 15. Multiple Choice Edit 1 minute 1 pt Which list of processes result in genetic variation? differentiation, mitosis, and cell division crossing-over, recombination, segregation, meiosis & fertilization cleavage, fertilization, mitosis, differentiation differentiation, meiosis, crossing-over, mitosis
• 16. Multiple Choice Edit 1 minute 1 pt What regulates the growth and development process? starch, iodine, benedict's, glucose ATP, amino acids, simple sugars crossing-over, mitosis, & differentiation genes, hormones and cell location
• 17. Multiple Choice Edit 1 minute 1 pt What processes are responsible for the development of tissues, organs, and organ systems? crossing-over & meiosis mitosis & differentiation mitosis & meiosis fertilization & mitosis
• 18. Multiple Choice Edit 1 minute 1 pt Which processes occur only in organisms that reproduce sexually? meiosis & fertilization mitosis & DNA replication mitosis & mutations meiosis & DNA replec
• 19. Multiple Choice Edit 1 minute 1 pt How are mitosis and meiosis similar? both produce gametes both require DNA replication both go from 2n to n both are required for asexual reproducction
• 23. Multiple Choice Edit 2 minutes 1 pt In a human bone, cell division is responsible for reproduction production of gametes growth and repair production of pollen
• 24. Multiple Choice Edit 2 minutes 1 pt In a single-celled organism, like bacteria, cell division is used for growth repair sexual reproduction asexual reproduction
• 25. Multiple Choice Edit 2 minutes 1 pt Identify the fertilization & embryonic development of humans. external fertilization & external development external fertilization & internal development internal fertilization & external development internal fertilization & internal development
• 26. Multiple Choice Edit 2 minutes 1 pt Identify the fertilization & embryonic development of birds. external fertilization & external development external fertilization & internal development internal fertilization & external development internal fertilization & internal development
• 27. Multiple Choice Edit 1 minute 1 pt How many chromosomes are in human body cells? 23 46 48 22
• 28. Multiple Choice Edit 1 minute 1 pt How many chromosomes are in human gametes? 23 46 48 22
• 29. Multiple Choice Edit 1 minute 1 pt What process produces gametes? fertilization mitosis meiosis metamorphosis
• 30. Multiple Choice Edit 1 minute 1 pt Abnormal, uncontrolled cell division results in gametes offspring cancer sex cells
• 34. Multiple Choice Edit 1 minute 1 pt Human eggs and sperm are _____, and each has ____ chromosomes. diploid, 23 diploid, 46 haploid, 23 haploid, 46
• 37. Multiple Choice Edit 1 minute 1 pt In mammals, the placenta is essential to the embryo for   nutrition, reproduction, and growth  nutrition, respiration and excretion  locomotion,respiration, and excretion  nutrition, reproduction, and excretion

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Reading & Math for K-5

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Fourth Grade Math Worksheets

Grade 4 math worksheets.

Our grade 4 math worksheets help students  build mastery in computations with the 4 basic operations , delve deeper into the use of fractions and decimals and introduce concept related to factors.  

4 Operations

Place Value & Rounding

Mental Multiplication

Multiply in Columns

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Order of Operations

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Sample Grade 4 Math Worksheet

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About Homework

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Homework consists of school assignments that students complete outside of class time, ranging from worksheets and practice exercises to long-term projects that extend over an entire semester or year. It also includes time spent studying for tests as well as reading and writing to prepare for upcoming class discussions.

Homework can serve several purposes. Most teachers intend it to reinforce and extend understanding of material taught in class. Educators also emphasize that doing homework regularly helps students develop habits of self-discipline and time management.

Since the late nineteenth century, debates over the amounts and types of homework assigned have occurred periodically, usually around the concern that schools expect students to complete too much or too little homework. Scholars continue to... .  ( Opposing Viewpoints )

• Is homework beneficial?
• At what age should homework be assigned?
• How much time should be devoted to homework?
• Should parents help with homework?
• Should the amount of homework vary when a child has a learning disability?
• When it comes to assigning homework, a rule of thumb is to use the ten-minute rule--what is it and how effective is it? 
• Increasingly, more educational resources are available online. What is the impact for low-income students or students in rural areas with limited access to the Internet?
• In relation to homework, compare the methods of "rote learning" to "meaningful learning"-- what are the pros and cons?
• Next: Library Resources >>
• Last Updated: Feb 8, 2024 11:31 AM
• URL: https://libguides.broward.edu/Homework

4 th grade homework!!!

1 Answered Questions for the topic 4 Th Grade Homework!!!

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Strong solar storm could disrupt phones, produce northern lights in US this weekend

• Associated Press

CAPE CANAVERAL — A strong solar storm headed toward Earth could produce northern lights in the U.S. and potentially disrupt communications this weekend.

The National Oceanic and Atmospheric Administration issued a rare geometric storm watch — the first in nearly 20 years. The watch starts Friday and lasts all weekend.

NOAA said the sun produced strong solar flares beginning Wednesday, resulting in five outbursts of plasma capable of disrupting satellites in orbit and power grids here on Earth. Each eruption — known as a coronal mass ejection — can contain billions of tons of solar plasma.

NOAA is calling this an unusual event, pointing out that the flares seem to be associated with a sunspot that’s 16 times the diameter of Earth. An extreme geomagnetic storm in 2003 took out power in Sweden and damaged power transformers in South Africa.

The latest storm could produce northern lights as far south in the U.S. as Alabama and Northern California, according to NOAA.

By MARCIA DUNN, AP Aerospace Writer

The Associated Press is an independent, not-for-profit news cooperative headquartered in New York City. Our teams in over 100 countries tell the world's stories, from breaking news to investigative reporting.

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