Get a Reaction- Newton's Laws of Motion for Kids

We've all seen things move. We've all made things move. But what is the science behind it?

The activities in this Instructable are a great way of teaching kids how and why things move, through challenges that illustrate each of Sir Isaac Newton's Laws of Motion. It would be a brilliant precursor to the activities in this contest that create things that move, as kids will approach the tasks with an understanding of what they're trying to achieve and how science makes it possible.

The best thing about this lesson? It's a totally fun and legitimate class to teach in the run up to Christmas! Why? Because Newton himself was born on Christmas day. Happy Newton-mas, everyone!

This club was originally developed and delivered as a Saturday Science Club for children aged 5-9 and their accompanying adults. Our clubs inspire children to pursue science and are held in our brand new science centre in Oxford, England. We delivered our club as a 90 minute workshop, but you could integrate each of these activities into your syllabus in whichever way you choose.

This Instructable uses scientific terminology which you may want to introduce to your students. Important vocabulary has been underlined the first time it is used.

Supplies

Activity 1- Marble Mazes

Boards (tea trays or large, hard-backed books work well for this)

Lolly sticks

Blu-tack

2x cotton reels (or something of a similar size with which to prop up your board)

Small random objects (we use Lego bricks, keyboard keys, dominoes, etc)

Stopwatch or timer

Activity 2- Mini Golf

3d printed golf course holes or holes constructed from recycled materials

Masking tape

Golf clubs (you could always have a go at making some sort of device from things you have at home or in your classroom)

Recycled materials (optional)

Activity 3- Newton's Cradle

Lolly sticks

Marbles

Thread

Plastic beads

Glue gun with glue sticks

Scissors

Step 1: Newton's First Law of Motion

Newton’s First Law of Motion states that an object will remain at rest or in uniform motion in a straight line unless acted on by an external, unbalanced force.

What does this mean?

It means that things don’t move on their own! And when things are set into motion, they will keep moving until something makes it stop.

A perfect way to demonstrate this is by making a marble maze. When you place your marble on a horizontal board, it may roll around a little, but it won’t travel too far.

1. What would happen if you tip your board up or down slightly?

a) It will start to move downwards.

2. Why does it move in this direction?

a) There’s a force called gravity that makes the marble move downwards. In fact, gravity is one of the reasons why the marble stays on your board (rather than flying off into the air!) Gravity always wants to pull things directly down, but with the board tilted, friction causes the ball to roll slowly down the board before falling to the floor.

3. Did you know that on Earth, gravity always has the same amount of force? The force is 9.8 metres per second. This means, if you were to drop something from a height of 9.8 metres, gravity alone would make it hit the ground in 1 second. But this may not always happen… can anyone think why?

a. Gravity isn’t the only force that acts on falling objects. Watch what happens when I drop two pieces of paper: one is in a ball and the other is not. What happens when they are dropped from the same height at the same time? Why do you think this might happen?

Task: Build your own marble maze

At Science Oxford, we have our own marble maze kits which we put together and use in our clubs and lend out to local schools. The kits contain a range of items including wooden boards, cotton reels to support the boards, lolly sticks, Lego blocks, keyboard keys, and blu-tack.

You can create your own board using a normal tea tray or large hard-backed book. Lolly sticks are really handy to use but you can use any small items you have in your classroom/ around the house. Why not challenge kids to source their own materials?

Make it challenging:

- We like to set kids the challenge of keeping the marble on their board and in motion for at least as many seconds as their age in years. Use a stopwatch to record your times and make small changes after each attempt to see if you can improve your score.

- Change the incline of your board and assess how this affects your score.

- If speed= distance/ time, can you work out the speed at which your marble is travelling?

- Want to make an epic marble maze? Why not (safely!) prop up a table to create an incline and build onto it?

- The fewer materials you have, the more challenging it is to create a marble maze that keeps the marble in motion for a long time. You could introduce the idea of fair testing by giving each kid/group the same materials to work with.

Step 2: Newton's Second Law of Motion

Newton’s Second Law of Motion states that if an external, unbalanced force is required to produce a change in velocity, then an external unbalanced force causes an acceleration.

What does this mean?

It means that the harder you hit something, the faster it moves and for longer a distance!

But is hitting something so that it moves quickly and far always a good thing? We’re going to test this out by making our own mini golf course!

Your task:

You will work in table groups to, first of all, construct your hole of the golf course. You will have your 3D-printed hole and a roll of masking tape with which to construct your path. You can also use recycled materials to create tunnels, bridges and other obstacles. Then, we will all have a go at completing each other’s points on the golf course.

Feel free to keep score as you go; the fewer strokes you take to get the ball in the hole the better! What I really want you to think about as you play is how much force you want to apply to the ball in order to set it into motion. You may find you need to adjust how much force you apply in order to get the ball where you want it to be!

Recreating this project:

- Attached are .stl files of mini-golf holes which I designed in Tinkercad to be printed on a 3d printer. If you'd like to make this project more learner-led, you can have students design the holes themselves. These are quite an easy first project to teach Tinkercad basics as you only have to insert basic shapes and cut holes (using a cylinder shape).

- If you'd prefer not to 3d print the holes, kids can construct them using recycled materials.

Step 3: Newton's Third Law of Motion

Newton’s Third Law of Motion states that for every action there is an equal and opposite reaction.

What does this mean?

Imagine rolling two footballs towards each other. When they hit each other, they’ll bounce back and start rolling in the opposite direction. This is because the energy transfers from one ball to the other. Equally, if two of you were to run into each other at speed, you'd end up bouncing backwards before falling to the ground (we'll just take my word for this; there's no need to demonstrate...)

The same thing happens with a Newton’s Cradle; when you swing one of the ball bearings, the energy transfers to the one it hits. What you will notice is that the middle ball bearings don’t appear to move much, whereas the ball bearing at the end will move with a similar momentum as that applied to the first.

Did you know that the Newton's Cradle wasn't actually named or invented by Isaac Newton? It was actually named by a guy called Simon...

Task:

We are going to have a go at building our own Newton’s Cradles. This will require children and grown-ups to work together. Some parts are quite fiddly and we will be using hot glue which you need to use carefully.

Take a look at the attached photos for visual instructions for how to make your own Newton's Cradle.

1. Construct your frame from lolly sticks and hot glue. Make sure it is the same height on both sides and that your base is as square as possible.

2. Glue a bead on to each of your 5 marbles. I used Hama or hot beads as they are a good size. You will then thread your string through the beads to hang your marbles from your frame.

3. Hang your marbles from your frame so that they are just touching each other and are hanging close but not touching the table.

4. Test out your Newton’s Cradle and check the marbles are set into motion as you’d hope. When you are happy with where your marbles are positioned, use hot glue to secure them to your frame.

Top tips:

- When preparing for this club I created a few of my own Newton's Cradles, with varying degrees of success. I found that a few things were key to making the cradle move effectively: using the same size and weight marbles, spacing the marbles evenly, hanging the marbles low down but not touching the table, having the marbles *just* touch each other.

- Rather than be too prescriptive in how to make the Newton's Cradle, I showed my examples to families and then, at the end, we had a go using each other to create our own 'success criteria' for a good, working, Newton's Cradle. Extra points to those who can give some ideas why it needs to be built in this way to work!