Engineering Challenge!

18 02 2011

This Saturday, we are celebrating National Engineer Day at the museum. You can celebrate this day with us by participating in an engineering challenge!

Civil engineers design and build big infrastructures like buildings, bridges, tunnels and dams. This takes a lot of work and requires a lot of planning and thinking.

When an engineer builds a bridge, the engineer has to think about all of the people that will be driving on that bridge. The bridge has to support people and cars, so it must be sturdy for safety.

We are challenging you to test the sturdiness of paper in different shapes!

The only supplies you will need are paper, tape and books. We used our paper and tape to design three different shapes. We chose to make a triangle, a cylinder and a square box.

We used old cards to create our shapes.

After we designed our shapes, we tested how sturdy each shape was by placing books on top of them.

The cylinder.

The triangle.

The square box.

We found the cylinder was very sturdy and could hold the most books!

You can also try to use different materials to design your shapes, and you can try to balance different things on top of them.

What did you discover about civil engineering in this challenge? Be sure to let us know!





Mini Marble Machine

16 02 2011

We love this marble machine made out of a cereal box that we spotted at Made By Joel. He has a great tutorial on how to make it! For ours, we cut out multiple holes in the lowest ramp and positioned it at an upward angle—we wanted to see if we could make the marble could fall into the second or third hole instead of the first.

Getting the marble in the second hole was not too hard, but we still haven’t been able to get it in the third hole!





Marble Races

29 01 2011

Ready, Set Roll! opened at 10 a.m on Saturday! Come on by and see all of our new activities!

In this video, we have some of the staff practicing physics in our new exhibit Ready, Set, Roll!

As you can see, it wasn’t so easy to hit the rotating buckets. Do you think it was the length of the tracks? Was it the height of the starting point? Which track do you think would make the golf ball fall faster?

For a way to test it at home, continue reading! Read the rest of this entry »





Make a Pendulum

20 01 2011

The Pendulum Snake is one of our favorite parts of the Notion of Motion exhibit. This is the exhibit’s last week here at the Museum, so we wanted to explore pendulums more by making one!

Materials you will need:  a small paper cup, a long piece of string, something to weigh down your cup (we used coins) and a piece of tape.

2 holes!Poke two holes in your cup. They should be across from each other.

thread through the holes!

Thread your string through both holes.

Tie a knot.

Fill the cup with your weights. You could also use rice or beans or sand as weight. Now your pendulum is ready! Hang it up in an open space. You can experiment with the length of string and amount of weight in your cup. What makes the pendulum swing faster? Slower?

Or, you can follow the link to make pendulum art like we did!

Read the rest of this entry »





Static Magic Trick

10 01 2011
Yesterday was National Static Electricity Day and we just can’t seem to stop celebrating. You’re probably familiar with static electricity. Have you ever gotten a shock after wearing socks on carpet then touching a friend? Have you ever combed your dry hair and noticed it stick up in the air? That’s static electricity at work.
So what exactly is static electricity? To understand static, we must first understand a little about atoms. Everything is made up of atoms. Atoms are tiny particles that are made up of protons, electrons, and neutrons. Protons have a positive charge, electrons have a negative charge, and neutrons are neutral.
Since everything is made up of atoms, and atoms have charges, all things have charges. Opposite charges attract and like charges repel (magnetic train sets are a good example of this attraction and repulsion). Most of the time, the positive and negative charges in an object are balanced, so the object overall is neutral.
Static electricity occurs when there is an imbalance of negative and positive charges in an object. Rubbing certain materials together can transfer negatively charged electrons and cause an imbalance. When you rub your socks on the carpet, you pick up extra electrons. The extra electrons want to be released, but can only leave your body when you come into contact with something else that conducts electricity.

We tried a not-so-shocking static magic trick here at the Museum.

All you need is a plastic straw in a paper wrapper (or, a plastic straw and a paper napkin).

Tear off the ends of the straw’s wrapper (or wrap your straw tightly in the paper napkin) and slide the straw band and forth through the paper quickly. Keep sliding the straw, about a dozen passes through the paper.

Take the straw out of the paper and hold the straw in your hand. Slowly open your fingers, and the straw should be “stuck” to your hand.

When you rubbed the straw, you made the straw negatively charged. Bringing the straw close to your hand causes your palm to become positively charged, and since opposite charges attract, the straw sticks to your hand.

Rub the straw again – see if it will stick to other items around the house – a wall, a door, etc.





What Can Water’s Surface Tension Do?

14 12 2010

Water particles are attracted to each other from all sides. The particles on the surface only have each other to bond with, because there are not particles on top of them.  This attraction creates a thin skin, called surface tension.  Very light objects, like paper clips, can float on water if they do not break the surface tension.

When you simply drop a paperclip into a cup of water the surface tension breaks, causing the paper clip to sink.  It is possible to gently lay a paper clip on top of the water. This is very difficult, because if  your fingernail touches the surface you will break the tension. One trick is to lay a small piece of paper towel on top of the water and then pace the paperclip on top. This allows the paperclip to gently ease 0nto the water. The paperclip will float even after the paper towel sinks to the bottom!

Do you have any other tips for making a paper clip float? Leave a comment letting us know.





How to Keep Apple Slices Looking Fresh

9 12 2010

Last Friday we learned about how copper in pennies reacts with oxygen in a process called oxidation, making the pennies darker.  Oxidation also causes apple slices to turn brown.  We are going to experiment to see what liquids can prevent apple slices from browning.

After cutting the apple, I submerged each slice in a different liquid.  I used one slice as my control sample, this slice was not placed in any liquids. Once the control had turned brown I compared it to the other slices. In the photo below the two slices on your right are the control.

Lemon juice contains citric acid which slows down the oxidation process so the slices do not turn brown. The lemon lime soda also contains lemon juice, so it has a similar affect. Can you think of any other mild acids that you could test?  The corn syrup coated the slice shielding it from the oxygen, limiting the oxidation process.

Try this experiment at home and leave a comment describing your results.





Make Frost Inside

7 12 2010

It is getting cold outside and you might notice frost on the car windows in the morning. You can make your own frost inside your warm house!

Find a clear plastic cup or glass and fill 2/3 of it with ice.  Next add water and sprinkle in rock salt. Stir the icy salt water mixture and wipe the out side of the cup with a paper towel so that it is dry.

Wait fifteen minutes and rub the outside of the cup, checking for frost. It might be hard to see in the picture, but the cup is frosted, and there are two vertical lines where I have rubbed the frost away.

Salt lowers the freezing point of water making the water in the cup colder than it would be without the salt. This speeds up the formation of frost on your cup.

What is your favorite part of winter weather? Leave us a comment letting us know.





Polishing Pennies

3 12 2010

Have you ever noticed that new pennies are shiny and old pennies are darker and sometimes even green. When copper is exposed to oxygen it oxidizes creating a darker layer of Copper Oxide on the outside of the penny. I experimented with several liquids to see if they could make the pennies shiny again.

Get several clear cups and dirty pennies. Try to find pennies that are similar in color, so you can compare how the liquids affect the pennies. Put a different liquid in each cup. I used lemon juice, vinegar, water, and dishwasher detergent mixed with water.

Put the pennies into the cups and wait of five minuets. I put two pennies in the liquids, so I could see if they came out the same. You could use more or only one. After the five minuets I took out the pennies and cleaned them off with a paper towel.

Look how shiny the pennies that were in the lemon juice are! Lemon juice has acidic acid which dissolves the copper oxide. Share your results with us in a comment. What liquids did you use?





Ocean Art: Using Wax and Water

26 11 2010

Have you ever noticed water droplets pooling up on the top of leaves and dripping off? The waxy layer on the outside of leaves is called the cuticle and makes the leaves waterproof. This keeps moisture inside the plant, allowing the rain water to soak into the soil and into the pant’s roots.

You can see wax repel water through this art project.  I drew fish using crayons, markers and colored pencils.  Crayons are made from wax.

Then I painted over the picture with blue watercolor paint, so it looks like it is under the ocean.  You can see how the yellow fish repelled the paint. The purple marker smeared a little, because it was also water based and mixed with the paint.

Leave a comment letting us know what you discovered when making your own creation.





Balancing Butterfly

22 11 2010

We have explored balance by making tops and balancing  yard sticks on our fingers. Now we are going to learn about center of gravity by making a beautiful butterfly

Fold a piece of paper in half and draw half a butterfly on one side. Cut out your butterfly, so that it is symmetric. Trace the butterfly onto a piece of cardboard.

After you cut out the butterfly try to balance it on the eraser side of a pencil. The butterfly’s center of gravity is the point where it can balance on the pencil. Next, tape one or two pennies onto each of the wings near the top.

Find the center of gravity again using the pencil. How did the weight change the center of gravity?





Weigh in on this Balancing Act

15 11 2010

Challenge a family member to see who can balance a yard stick on one finger for the longest amount of time, using science to your advantage.

First, remember to look at the top of the stick while balancing. This way you will know as soon as the stick starts to fall and have more time to react.

Secondly, add weight to the top of the stick. When the weight is farther from the center, it has more inertia and is more likely to stay at rest. In this example your finger is the center.

 

We had fun exploring different ways to add weight to the stick, using clay.

Do you have anymore tips on how to balance a yard stick on your finger? Leave a comment so we can experiment with your idea.

Also, there is a Notion of Motion exhibit that illustrates this same principle using wheels. What wheel do you think will start rolling the fastest? The one with the hole in the middle, placing the weight on the outside, or the disk with evenly distributed weight? Try it out!





Why don’t we see Craters on Earth?

12 11 2010

It is easy to find craters on the Moon, but we do not run across them on Earth very often.

Photo Credit: NASA

 

One reason there are not many craters on the Earth is that few meteors pass through the Earth’s atmosphere. The Moon does not have thick gasses forming a protective atmosphere like Earth. Another important difference in between the Moon and the Earth is that it rains on Earth.

Try this experiment to see how rain affects craters.

Put powdered sugar or baking powder into the bowl, filling it a little over an inch high. Next, cover up the sugar with a thin layer of cocoa powder or brown sugar.

Put the bowl on a piece of newspaper, or go outside,  so you do not make a mess while creating your crater. Drop pebbles, representing meteors,  into the bowl. Watch as the impact of the pebbles creates craters.

Now spray the surface with a water bottle to see how rain affects craters.

The brown sugar is filling in the crater so that the surface is more even again. How do you think rain and wind affect craters over thousands and thousands of years?





Point out this Optical Illusion

10 11 2010

Make this optical illusion and share it with a friend. Carefully  cut a pipe cleaner  so that  the two pieces are the same length. Next take a different color pipe cleaner and cut it into four equal parts.

Take one of the longer pieces of pipe cleaner and wrap the tip around the middle of one of the smaller pieces. fold the smaller pipe cleaner to form an arrow. Do the same thing for the other side, so it looks like this <–>. Repeat using the second pipe cleaner only this time bend the ends of the smaller pipe cleaners out like this >–< .

Does one of the orange pipe cleaners look longer than the other? Why do you think that is?

If you liked this optical illusion try using Persistence of Vision to create the illusion of movement!





Can You Top This?

8 11 2010

Have you ever thought about what makes a top spin for so long? Experiment making your own top using paper plates, pencils, paper clips, pennies, and whatever else you can find.

One things we found while experimenting is that it is better to keep the top short and close to the ground. Also, it is important for it to by symmetrical, or the same on all sides. What did you notice when you tried to make your own top? Leave a comment so other readers can try it.

 

We experimented with our tops on the turntable. Bring up your own top and give it a spin!

 








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