Design Challenges

Hey there, Tinkerers!

Ever wonder how satellites and spaceships are able to turn and change their paths in space? Check out this design challenge and see if you can do the same thing with magnets and a steel ball!

After you're done with the last one, here's another cool design challenge to check out. Try designing your own robotic arm to pick things up.

Let us know how it goes in the comments section! Did your design work? Or did you think of a better way of building it?  Maybe you used more than one magnet to steer your ball or different materials for your robotic arm. Try different things and see which design works best. Happy Tinkering!

Make your own bicep!

Biomedical engineers try to understand how the body works so they can fix it with artificial parts when it gets damaged. One of the important types of body parts is muscle. When a muscle is stretched too much, or strained, it might need a biomedical device to get better. Sometimes a device can act like a muscle and help your strained muscles rest and heal faster. Try out this activity to make an artificial bicep!

Make your own Rubber Band car!

How can you make a car with just things around your house? Read on to find out!

The Experiment

Materials:

• 2 paper or plastic cups with lids
• Scissors
• Duct tape
• Stick
• 3-4 rubber bands
• 1 paperclip
• beads with big holes
• Pen or pencil

Try it out:

1. Cut out a small hole on the bottom of each cup. Make sure that the holes line up when you put the bottoms of both cups together.
2. Tape the bottom of both cups together.
3. Poke holes in the center of the lids of both cups. 
4. Connect the rubber bands together by looping them into each other, making a chain. You can do this by putting one rubber band half way through the other, and tucking one end through the center, like this: 
   
5. Thread the rubber band chain through the one lid, the hole in the bottom of the cups and the other lid.
6. Loop a paper clip through one end of the rubber band chain to stop it from going into the cup. 
7. On the other end, put a bead in the rubber band, and then put the stick through the remaining end of the rubber band loop. Your finished car should look something like this:
   
8. Twist up the rubber band and let the car go! 

What's happening

When the rubber band is twisted, it is storing potential energy. Potential energy is energy that is stored in an object. When the rubber band is released, this energy gets turned into mechanical energy. Mechanical energy is energy that does work. 

The only place this energy can be let out is in the paper cups, causing the paper cups to turn, making your car move forward. 

If you thought this was cool...

This project is related to mechanical engineering. You can find out more here. Some concepts used in this project are potential and mechanical energy. You can find out more about energy through this project.

Make your own Marble Run!

Can you get a marble to drop into a cup from the other side of the room? Try out this experiment and find out!

Tackling Friction

Friction is a force that helps things slow down when they're moving. Friction is what makes your brakes work on your bike or car, and what helps a ball roll on the ground. But what happens when you want to have less friction? Try out this experiment and see if you can figure it out!

The Experiment

This experiment is based on a similar experiment by education.com.

Materials:

shoebox
balloon
scissors
straws
tape
ruler

Try it out:

1. Ask an adult to help you cut a small hole on one side of the box. This is where the end of the balloon will stick out.
2. Put the balloon through the hole so that the large part of the balloon is inside the box and the end is sticking out.
3. Blow up the balloon, then hold the end closed with your fingers. Put the box on a flat surface, like the floor, and use tape to mark the starting point.
4. Let go and measure how far the box travels. Try this a couple of times.
5. Now cover the floor with straws like this. You'll need at least 3 feet of straws:

    6. Place the box and balloon on the straws and see how far they go this time.

    7. Finally, glue or tape two straws to the bottom of the box like a sled

   8. Place the box and balloon back on the floor and see how far they go.

Which box went the farthest? Why do you think that is?

What's happening

Friction is a force that acts in the opposite direction as the direction something is moving. When the box moves forward, friction pulls it back. The stronger the friction is, the less the box can move.

What makes friction stronger? There are a couple of different things. One is how rough the surface is. A rough surface like carpet or the street will have more friction than a smooth surface like a wood floor. When you pushed the box on the lined up straws, the straws roll around and have very little friction because they are very smooth.

Another is the surface area of the object that is touching the floor. If the surface area of the object is bigger, that means the friction can push on a big area, which makes the friction stronger. When you glued the two straws on the bottom of the box, you gave the friction less surface area to push on. That makes the friction weaker so the box can move farther.

If you thought this was cool...

This experiment is related to mechanical engineering. You can find out more here.
Some ideas from physics in this experiment include forces and friction.

Toothpick towers

How tall can you build a tower out of just toothpicks and marshmallows? Try out some of these ideas and see how far you can go!

Make your own balloon-powered car!

Here's how to make a car that's powered by balloons! Can you get your car to move? How far does it go?