Force and Motion: Newton's Second Law

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Science Objects are two hour on-line interactive inquiry-based content modules that help teachers better understand the science content they teach. This Science Object is the third of four Science Objects in the Force and Motion SciPack. It provides a conceptual and real-world understanding of Newton’s Second Law of Motion. An object’s change in motion is proportional to the net force applied to the object and inversely proportional to the mass of the object (being the measure of its inertia). The magnitude of the change in motion can be calculated using the relationship F = ma, which is independent of the nature of the force acting on the object.

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Reviews (38)
  • on Tue Jun 27, 2017 11:28 PM

Newton’s first law of motion tutorial is effectively explained how a force is needed to overcome inertia (the tendency to resist any change in motion). Newton’s second law tutorial gives more concrete and mathematical descriptions and demonstrations of what happens when an unbalanced force actually does act upon an object. In the second tutorial, I found it extremely helpful how the tutorial began with the spaceship simulation activity. I felt this simulation will be an easy and effective way to “hook” students’ inquiry of the second law. This is a great way for students to learn it, manipulate it, and verbalize it in their own terms!

Kim Rivera  (Midlothian, TX)
Kim Rivera (Midlothian, TX)

  • on Fri Feb 20, 2015 8:12 AM

Although I thought I understood this law, the formative assessments along the way helped me to uncover my own misconceptions. By recognizing how I can misunderstand a concept I can be better prepared to guide my students. I wish I had this kind of resource when I took physics in high school, but then again, at that time we were still using a slide rule to calculate F=MA. Sad, but true.

Robin Willig  (Rye Brook, NY)
Robin Willig (Rye Brook, NY)

  • on Tue Sep 02, 2014 7:26 AM

I really enjoy Science Objects. In 1-3 hours, the Force and Motion: Newton's Second Law Science Object will help me re-learn, refresh, or learn for the first time some critical science concepts I will have to know to obtain my Science Educator credentials. I appreciate that I can complete them at my own pace, and that, if used as park of a SciPack, I have access to a content expert to go to for help. The NSTA Learning Center Science Objects are very beneficial!

Naomi Beverly  (Marietta, GA)
Naomi Beverly (Marietta, GA)

  • on Thu Dec 30, 2010 5:36 AM

F=ma in terms I can understand! The language used in this science object is clear. There are multiple opportunities to make sense of Newton's Second Law.

Donna W
Donna W

  • on Fri Apr 30, 2010 1:39 PM

I enjoyrd this science objective in that it clarified some misconceptions. I remebered the formula F=ma but did not understand the role of opposing forces. I now realize that the F stands for a net force and so any opposing forces needed to first be subtracted in order for the equation to be balanced. Very interesting.


  • on Wed Apr 28, 2010 6:32 PM

After reviewing this article, I have a much clearer understanding of the relation between inertia and mass. Prior, they seemed synonymous. Now knowing that massis simply the "numerical version" of inertia it sems quite simple. I will definitely be using the spacecraft demo and the balloon demo in my classroom. The students should understand how adding members in the spacecraft decreases its acceleration. The activity/competition should be fun when the students try to have all 3 crafts crossing the finish line together. Manipulating the mass should "click" with them in seeing the increase/decrease before their eyes. Same is true with the balloon demonstration. They'll be able to see the more balloons added the greater the thrust/acceleration. Likewise, an increase in washers creates more friction which in turn decreases the acceleration. I believe with using smaller numbers and applying the fomula F=MA will increase their understanding as well; knowing 2 components, they'll be able to back into the 3rd/missing number.

Denise H  (Piscataway, NJ)
Denise H (Piscataway, NJ)

  • on Thu Mar 25, 2010 12:14 PM

In Newton’s first law of motion tutorial, it effectively explained how a force is needed to overcome inertia (the tendency to resist any change in motion). Newton’s second law tutorial gives more concrete and mathematical descriptions and demonstrations of what happens when an unbalanced force actually does act upon an object. In the second tutorial, I found it extremely helpful how the tutorial began with the spaceship simulation activity. I felt this simulation will be an easy and effective way to “hook” students’ inquiry of the second law and its components. Plus, this activity could extend itself into wonderful engineering performance task in the beginning of a lesson, as well as, a culminating activity. This will help determine students’ knowledge of the law after studying it. Another one of my favorite components of this tutorial is the “Common Student Preconception” section. This allows the instructor to foresee where students may run into difficulty in understanding the law. Also, since this law is quantitative by nature (which often deters students who do not feel confident in math), the teeter totter simulation is an easier way to think about keeping the balance within the equation without primarily computing the numbers. I definitely plan on using this tutorial when teaching Newton’s second law. Thanks!

Lisa G
Lisa G

  • on Wed Mar 24, 2010 3:30 PM

The simulation activities were very challenging, enjoyable and thought-provoking. The concepts that I learned from this article enlightened me more.It will all depend on the teacher to suit the activities apt for the level of the students especially the computational part. I love doing this to enriched the application of multiplication facts especially in grade 3. Thank you.

Ida Barrera
Ida Barrera

  • on Tue Mar 16, 2010 1:59 PM

NSTA used a tutorial of 3 space ships to show F=ma. The spaceships had different masses and forces. Our challenge was to make all the spaceships move at the same speed. In order to make the spaceships move at the same speed, the force and mass had to be equal. I would use the ping pong ball and golf ball activity suggested to explain the concept easily to my students, since I don’t have the spaceships available.

Antoinette M
Antoinette M

  • on Tue Mar 16, 2010 1:53 PM

Of all Newton's Laws of Motion, this 2nd one has always been the most difficult for my kids to grasp. They struggle to understand the relationship between force's strength, an object's mass, and amount of change in an object's motion (acceleration). However, I found this tutorial to be very informative and helpful. SO I try to find better, more creative ways of presenting this lesson. The interactive simulations really showed the relationship between force, mass, and acceleration and how changing or applying different variables can affect their balance. I did the hands-on activity with the jet balloons in my class and my students seemed to understand the relationship better. I can show the interactive simulations on the StarBoard in my class and have students change the variables and see different results. This tutorial definitely helped me understand this law better, as well as gave me new ideas to apply in my class.

Maria Palanca
Maria Palanca

  • on Tue Mar 16, 2010 1:49 PM

This tutorial was a little more difficult to follow that the first. The concept will be harder to teach third graders, but using some of the activities will definitely help. A good activity to start with would be the ping pong ball force/acceleration activity. Simple and to the point. I would like to try this with different size balls and applying different forces. I will have students name objects with different masses so they understand this concept. The balloon rocket activity is a neat thing to do to show acceleration. They will actually be learning something while they are having fun!

Nancy Mielnicki
Nancy Mielnicki

  • on Tue Mar 16, 2010 1:33 PM

Of all of Newton’s Laws, this was the most difficult concept to teach and the most difficult for my fifth grade students to understand. The Newton’s Second Law tutorial was very enlightening. After reading through the information and utilizing the interactives, it is easy to recognize how I could incorporate these lessons to aide in my students understanding. The information to be learned was presented in an easy to follow format with clear and concise language for understanding the relationship between force, mass, and acceleration. Each new concept was accompanied by interactive simulations and online quizzes that were also very helpful. I am looking forward to placing this information on my Smartboard and allowing my students to gain new understanding of this law.

Jacqueline Docampo
Jacqueline Docampo

  • on Tue Mar 16, 2010 11:29 AM

The article gave quite an insight to this law. It applied to a wide range of physical phenomena. The activities helped enhance the readers understanding of the concept. I took the students into the computer lab so they could use a student-friendly site which contained reading and activities on their ability level. For this law I placed a stone on lined paper on each desk and asked the students to move it using only their breath and record the distance it traveled. Then we replaced the stone with cotton balls and repeated the above. The students noted that the greater the mass (of the object being accelerated) the greater the amount of force needed (to accelerate the object).


  • on Tue Mar 16, 2010 11:24 AM

I tied this article into the activities we learned this summer at our PISA workshop. When two people of the same mass push against each other, neither move. When a larger person pushes against a smaller person the smaller person moves. In my lab class I have the students first try to move an eraser by blowing on it. Given that the eraser has a greater mass than the student's breath, the eraser does not move. Next I trade the erasers for cotton balls and tell the students to blow once again. This time the cotton balls move due to the amount of force exerted from their breath.


  • on Tue Mar 16, 2010 11:03 AM

Fascinating! This tutorial was absorbing. The video demonstrations were so helpful in understanding Newton's 2nd Law of force, mass and acceleration. When a state of rest or motion changes, it must be due to the action of a net external force. The JetToy activity learned at PISA would be an excellent way to demonstrate this principle in the classroom.

Maryanne  (Bayonne, NJ)
Maryanne (Bayonne, NJ)

  • on Sat Mar 13, 2010 6:01 PM

I always felt that Newton's Second Law was hard for elementary students to understand, probably because I didn't seem to understand it as well as Laws 1 and 3. This tutorial has changed my mind, the Rocketship simulation is perfect. The balloons and washers is also very understandable. I was also under the misconception that Force was being transferred from one object to the next and this tutorial has shown me that tis is a misconception. I learned a lot from this tutorial and I found the math very understandable also.

Barbara Henderson  (Jersey City, NJ)
Barbara Henderson (Jersey City, NJ)

  • on Sat Feb 20, 2010 2:53 PM

The tutorial gives detailed description on how forces affect changes in motion, particularly how the different kinds of forces create the net force on an object. Among the three laws of Newton, the second law explains the relationship between force, mass, and acceleration mathematicaly. I find this law easy to teach. The tutorial gives simulations, hands-on, activities and illustrations which will be very useful to the students. These will give them direct experience to observe and understand the formula. This experience will enhance the students' qualitative undersatnding of F=ma.

Isabel Ramos  (1601 Central ave. Union City, NJ)
Isabel Ramos (1601 Central ave. Union City, NJ)

  • on Sat Aug 08, 2009 6:58 AM

These SO's make sense and will help me to decide what to focus on in the classroom. Have to have the 'big ideas' rather than just a lot of hands-on activities. This will help us focus. NY state standards are broad.

Liz M  (Interlaken, NY)
Liz M (Interlaken, NY)

  • on Fri Aug 05, 2016 5:06 PM

Good review and ideas for teaching to students

Stacey  (Bay City, TX)
Stacey (Bay City, TX)

  • on Tue Mar 11, 2014 9:06 PM

A short course reviewing Newton's second law. I liked the quiz questions (neither too easy nor too hard) and the example of the golf ball and the ping ball ball. Overall a great science guide!

Emily Keeter  (Northbrook, IL)
Emily Keeter (Northbrook, IL)

  • on Fri Dec 30, 2011 12:57 AM

The way the formula was presented for Newton's second law was creative and easy to implement in the classroom. Some of the questions were a little tough to make sense of, but once you got the hang of it, it was ok. Great resource

Brandy Stewart
Brandy Stewart

  • on Fri Apr 30, 2010 8:53 AM

Mass and inertia go hand in hand. The more massive you are, the more inertia has net forces gives objects acceleration and speed, but it can also change the course of the direction. If you have a big net force, there could be a big change in direction. It’s sort of like a bigger slam to your car, more denting damage to your bumper. In terms of friction with the net force and mass, Newton’s Second Law is the least complicated for this simpleton’s brain. It’s also like the car chases in the movies, when a car is turning corners, they leave the evidence of friction on the pavement-displaying friction is larger on a curve. Being an educator to third graders, applying the formulas F = ma won’t go too far; however throwing in balloons, index cards, and straws in the mix of Newton’s Second Law, we’re going to have a FORCE FIESTA! The balloon rocket activity was something that I will definitely take back into my classroom. It was a very interactive lesson I enjoyed over the summer, when I did it with my colleagues at Stevens Institute-Summer 2009 PISA program.

Francine Yu
Francine Yu

  • on Thu Apr 29, 2010 6:36 PM

The tutorial for Newton’s Second Law, especially the diagrams, were very helpful. This law is much easier for me to comprehend. The math equations are still difficult, however, the concepts are easy to come across in real life. After watching the tutorial, I feel more comfortable teaching this material to my students because I am confident that I understand it myself. The activity that I would use to teach mass and acceleration to my students is the rocket balloon. We did this activity during the PISA Institute and it was also in the tutorial. During the summer, my group tried several different options, but when we had two balloons with a little amount of tape, our rocket accelerated the quickest. Now I realize it was because there was more force with two balloons than with one and there was very little mass slowing it down.

kelly  (hoboken, NJ)
kelly (hoboken, NJ)

  • on Wed Apr 28, 2010 8:25 PM

I found this one more difficult to understand but I was not overly familiar with the second law. Too many technical terms but the videos were very helpful. I will have to review this one again prior to teaching it to the class. Demonstration are wonderful too.

Jean O  (Jersey City, NJ)
Jean O (Jersey City, NJ)

  • on Wed Apr 28, 2010 12:20 AM

The first law talked about inertia not being a force. This law helped to assign a value to inertia. The simulation with the spaceships was excellent...I was able to use it in my class as it was easy to understand & introduced the vocabulary words force & mass. I learned that an object's mass is a measure of the object's inertia. I learned about the mathematical concept amongst the relationship between net force and changes in motion learning that the net force acting on an object = mass of the object/acceleration of the object; F = m a The "Horizontal Balloons" simulation reminded me of the balloon experiment done at PISA. Where F represents the net force, m represents the mass, and a represents the acceleration.

Jennifer M  (Bayonne, NJ)
Jennifer M (Bayonne, NJ)

  • on Tue Mar 16, 2010 1:42 PM

The activities for Newton's Second Law were insightful and gave fun examples for the students to grasp this concept. The Revisiting an Explanation was useful for checking understanding. However, a few of the questions that were posed after could be difficult and cause confusion because they were partially true. The Hands on Activity is a good way to further enhance the learning process.

Natalie V
Natalie V

  • on Tue Mar 16, 2010 1:38 PM

This second law of Newton's, demonstrates to students how we can incorporate math, reading and science. This is where I believe math and science will start to make sense to students. ( F/m=ma/m=F/m=a). Using everyday problems, students can see how important math and science is. Now they can't say "why do I have to learn this"?

Priscilla Jones
Priscilla Jones

  • on Tue Mar 16, 2010 12:59 PM

As I read the tutorial I noticed that the second law of motion is a bit more complicated than the first law of motion. F=ma is not easily understood no matter how it is explained. Finding the acceleration is confusing to me. The interactive simulations did help me to understand easier. I liked the link at the end of classroom resources. This will definitely come in handy for me with my students. My students would especially enjoy the balloon and aluminum can activity. I plan to demonstrate this to my class. I may go back and read the tutorial again for a better understanding. The author couldn't have put it in simpler terms, therefore; a second read would be beneficial to me!

kathleen jorgensen  (, )
kathleen jorgensen (, )

  • on Tue Mar 16, 2010 12:03 PM

I tied this article into the activities we learned this summer at our PISA workshop. We were given two balls that appeared to be exactly the same- size and mass. When we dropped them at the same height, they reacted differently. The ball with the greater mass did not bounce back up whereas the ball with less mass bounced. In my lab class I have the student’s first try to move an eraser by blowing on it. Given that the eraser has a greater mass than the student's breathe, the eraser does not move. Next I trade the erasers for cotton balls and tell the students to blow once again. This time the cotton balls move due to the amount of force exerted from their breath.


  • on Tue Mar 16, 2010 11:26 AM

I had more difficulty determining how to incorporate elements of this tutorial in my classroom, in comparison to “Newton’s First Law.” The concept of force equals mass times acceleration is a formula that many of my students will be able to apply, but I feel that the concept behind the formula may be difficult for some third graders to grasp. This tutorial was thorough in explaining net forces, and how an unbalanced force acting on an object will cause the object to accelerate. I enjoyed the spaceship simulation, and I feel that this demonstration will allow the students to understand that objects can accelerate faster with less mass. Once again, the quizzes were helpful in assessing my knowledge of the material, and I found the “Check Your Thinking” section a helpful review tool.

Dina M  (Weehawken, NJ)
Dina M (Weehawken, NJ)

  • on Tue Mar 16, 2010 11:14 AM

I found that the Second Law is more difficult to understand than the First Law. It's confusing that the same push or pull on an object doesn't result in the same motion because of the mass of that object. I can understand why this is a misconception with students since I am not fully understanding the concept. The spaceship illustration in the beginning of the tutorial helped me. Also, the list of objects from the most to the least mass put things into perspective for me. Finding the resulting acceleration of an object is still difficult for me. I do think that the rubbing of the balloon to your hair and putting it near an aluminum can will be a fun experience for the kids! I will definitely need to utilize the classroom resources before attempting to explain this Law of Motion to my students. The resources seem very useful!!

Vanessa Geerin  (, )
Vanessa Geerin (, )

  • on Sun Feb 28, 2010 3:04 PM

I had prior knowledge from PISA this past summer. We conducted the ballonn experiment to demonstrate the theory of acceleration. The tutorial cleared up some confusion on how force equals mass and acceleration. These concepts might be hard for me to teach to my third graders without the hands on activities to demonstrate them. I understand better now that the greater the acceleration = the more force and less mass and the less acceleration= less force and more mass or inertia.

Bess M
Bess M

  • on Fri Apr 30, 2010 8:54 PM

Maybe it was just me, but I was having a bit of trouble with answering the concept taught in this resource. Understanding that different forces effect the motion of an object particularly gave me trouble in the quizzes. Punching in numbers to figure out a formula is not hard to do, I was just a bit bothered that I couldn't get things answered correctly. The interactive modules are fine. I like the one with the balloons and washer.

Judith V
Judith V

  • on Wed Apr 28, 2010 8:03 PM

I now have a better understanding of force and acceleration. This tutorial helped to clarify that "when the force is increased the acceleration is increased" and "less (smaller) mass increases acceleration and larger mass decreases acceleration". However, I am confused with idea that mass and inertia are the same concept because I have believed that mass is anything that takes up space and inertia is related to the movement or lack of movement of an object. Another thing about Newton's 2nd Law is the section that explained applying the law this process seems easy enough to simply plug in the numbers for the given formula yet the task is not that simple as one goes further into the tutorial, because it seems to have an overwhelming amount of information and confusing terminology.

Gina Venable
Gina Venable

  • on Sun Apr 25, 2010 4:16 PM

The 2nd law says that the acceleration of an object produced by a net(total) applied force is directly related to the magnitude of the force, the same direction as the force and inversely related to the mass of the object.!!! This law I find to be confusing especially when you see the formula F=ma A=f/m. However,as I watched the videos that showed the spaceshiips,soccer balls, balloons and cars I remembered working on some of these activities during the 2009 PISA Institute workshop with Carol Sheilds(and Augusto).Doing those activities DID make it much easier to understand. Therefore, I have confidence that my students will feel the same.

kathleen  temple  (hoboken, NJ)
kathleen temple (hoboken, NJ)

  • on Mon Apr 05, 2010 12:29 PM

As a resource to refresh your knowledge on Newton's Second Law it was very good, however I don't think I could use it to help me in my fourth grade class. I would probably use the balloon rocket to illustrate what happens when variables are added . The teeter tooter could help me to illustrate that things happen only when there is an imbalance but the underlying concepts are too advanced for me to use in my classroom

Debra  Czerwienski  (Bayonne, NJ)
Debra Czerwienski (Bayonne, NJ)

  • on Sun Mar 07, 2010 3:04 PM

I found this tutorial a bit more confusing than Newton's First Law. In answering the questions, I seemed to get more incorrect answers this time around. I feel that the simulations and visual aide models were not as comprehensive as the last tutorial. The information was more in depth as well and required to you to build upon the knowledge learned on the previous pages. Calculations were needed to be performed, which were somewhat tricky in terms of remembering how many balloons/washers (newtons/kilograms) had to be calulated. Overall, I feel that I learned less in this object than the previous one.

nicole q  (jersey city, NJ)
nicole q (jersey city, NJ)

  • on Mon Jun 04, 2007 10:41 AM

The information is very dense--spread it out a little--start new lines . . . Include units Include an example or 2 Include FIND OUT MORE links to useful resources Then it will be very useful

Christine Hunt  (Potomac, MD)
Christine Hunt (Potomac, MD)

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