Tag Archives: TryThisTuesday

#TryThisTuesday: Colourful Flower Bouquet

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Last week, Street Scientist, Ailie, showed us how to make a colour wheel with kitchen roll. Now we’re going to use that same technique to create a colourful bunch of paper flowers.

How can we use the process of capillary action, and the coloured water we made last week, to do something creative? First, you need to make 6 flower heads out of kitchen roll by folding and cutting as below.

  1. First fold the sheet in half to make a rectangle.
  2. Fold the rectangle in half to make a square.
  3. The fold the square in half diagonally to make a triangle.
  4. Fold the triangle in half again.
  5. Cut the top of the small triangle into a round petal shape
  6. Unfold the sheet to reveal your flower.
  • Cut another sheet in half and twist it up to form a stalk. Then pinch the end of your flower head and tape the stalk to the flower.
  • Place the stem of each flower into one of the cups of coloured water from earlier. Put something underneath the flower heads to soak up any extra water, or do it outside if you can.
  • Come back in an hour and the water should have moved, by capillary action, throughout the whole flower. You can now remove the stems from the cups and leave them to dry.
  • Scrunch all the dried flowers you’ve made together, tape around the top of the stalks, and you’ve made a beautiful multicoloured bouquet.

#TryThisTuesday: Walking Water

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Our Try This Tuesday series of experiments to try at home is back with a colourful water-based experiment from Street Scientist, Ailie.

You will need:

  • Red, yellow and blue food colouring
  • Kitchen roll
  • 6 Clear cups, roughly the same size
  1. Add water to three of the cups so they are 3/4 full. Then add 5 drops of red food colouring to one cup of water, blue into the second and yellow into the third.
  2. Place the cups in a circle with the empty cups in-between the ones with water in (You may want to put some paper underneath the cups if you are worried about spills).

3. Take 6 sheets of kitchen roll and fold them twice to make a thick strip as below. You may want to cut them to be a bit shorter if you are using small cups, I cut off the bottom 1/5th.

4. Place one end of each strip of kitchen roll into one of the cups with water in and the other end into an empty cup next to it. Can you predict what colours might form in the empty cups?

5. Wait an hour then check back in to see if your experiment is working! Mine looked like this:

Eventually the empty cups will be as full as the cups feeding into them!

Colour Theory

Did you notice something the 3 colours you started with had in common? They are the primary colours. Therefore, mixing them creates the 3 secondary colours – purple, green and orange.

This gives us a simplified version of a colour wheel. The colours opposite each other on the wheel, and in our cup circle, are ‘complimentary’ meaning they contrast one another i.e. purple and yellow.

If we were to add more empty glasses in between the colours we have here we would make tertiary colours!

The Science

The water moves up the paper towel through a process called capillary action which is the ability of water to flow through narrow spaces, even against gravity! Capillary action works as molecules in liquid like to stick together (cohesion) and also like to stick to walls of a tube (adhesion). Together these forces act to propel the liquid through the tube or narrow space. The narrower the space, the quicker the water moves and the higher up it can go.

Plants rely on capillary action to move water all the way up from their roots to the leaves at the very top, where it is needed for photosynthesis (the production of glucose for energy). Just as humans have blood vessels to carry important substances around our body in the blood, plants have a tissue called xylem which is made up of millions of tiny tubes. Water moves up through the tiny cubes by capillary action, without wasting any of the plant’s energy.

One way to easily see capillary action working in the xylem is to cut the very bottom off the stem of celery or cabbage and put it into some water with food colouring. Given enough time, you will see the coloured water move to the top of the plant and stain the leaves. When a plant has been picked it is no longer undergoing photosynthesis and producing energy, therefore we have shown that the water is moving up to the top of the plant by a passive process.

Kitchen roll is designed to be very absorbent meaning it is able to hold lots of liquid – great for kitchen spills. To be able to do this, there are lots of little spaces in-between the fibres in kitchen roll which fill with water. Together they form the narrow spaces which the water uses to move up the tissue and into the adjacent empty cup. There, the colour mixes with the water from the cup on the other side to form our secondary colours.

Can you figure out how to make a colourful bunch of “flowers” out of your kitchen roll using this method? Check back for next week’s Try This Tuesday and we will show you!

#TryThisTuesday: Virtual Treasure Hunt

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To celebrate International Talk Like a Pirate Day we have put together a virtual treasure hunt that you can do from a phone or computer.

For this treasure hunt you will need to solve clues to find co-ordinates to the next stop . The first three people to make it to the end of the hunt will win the treasure of a Street Science Busking Kit which is filled with equipment to make amazing science demonstrations at home!

Using Co-ordinates

Geographic co-ordinates allow every place on Earth to be identified with a set of numbers. The system that we’re using for this treasure hunt gives every point a latitude number and a longitude number.

If you were to draw a line from your point on the globe into the centre of the Earth and another from the centre of the Earth to the Equator, the angle between these two lines gives you the Latitude.

Longitude is measured slightly differently.  There is an invisible line running from the North Pole to the South Pole through the Royal Observatory in Greenwich, London, known as the Prime Meridian.  All points along this line have the longitude 0. The longitude of other points are calculated as the angle east or west from the Prime Meridian.

So Newcastle Upon Tyne, where we’re starting our treasure hunt from, has the co-ordinates 54.97, -1.61 because it is 54.97 degrees from the Equator and 1.61 degrees to the west of the Prime Meridian. Going west of the Prime Meridian or south of the Equator gives the co-ordinate a negative value.

 

The Treasure Hunt

Try to solve the clues to find the co-ordinates for the next place. Once you’ve got co-ordinates type them into Google maps (just like this: 54.97, -1.61 with latitude first) and make a note of where you’ve got to.

This will test your research skills as well as your maths skills, feel free to use Wikipedia and a calculator.

Destination One

The latitude for the first place is 57.14 divided by the number of universities in Newcastle Upon Tyne.

The longitude is  equal to 10 – 90.65.

Where are you?

 

Destination Two

To find the latitude of our second destination, take the last two digits of the year the first man walked on the moon, half this number then add 3.32

The longitude can be found by taking the year Newcastle University became independent from Durham University away from the year that the oldest part of the university (the School of Medicine and Surgery) was established and adding 6.52.

What amazing feat of engineering are you near?

 

Destination Three

For the latitude of our next place, take away 3.1 from the distance that Destination Two stretches in miles.

The longitude can calculated by the number of different countries that students at Newcastle University have come from divided by -2.

Which wondrous forest have we arrived at?

 

Destination Four

The latitude of this place can be uncovered by multiplying the number of countries that share Destination Three by 5 then adding 1.234

The longitude is equal to the number of reptile species that have been discovered in our previous destination divided by 63 then add 0.053

What amazing discoveries were made here?

 

Destination Five

The above place is often known by an abbreviation of four letters. If you convert these letters to numbers (eg. a=1, b=2, c=3 etc.) and square the second number, then add 0.197 you will have the latitude of our next  destination.

To find the longitude, convert the first letter of the abbreviation to a number and take this away from 58.274.

Which incredible man made structure are you looking at now?

 

Destination Six

For the latitude of our final place – where the treasure is buried – you will need to divide the total height of the structure we just saw (in metres) by -46.1.

To find the longitude, simply take away 16 from the number of floors in this structure.

Where is our treasure buried?

If you think you’ve cracked it, either send us an email to stem@ncl.ac.uk or comment below with the six places the co-ordinates led you to!

 

#TryThisTuesday: Rice Bottle

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Our #TryThisTuesday this week, is a challenge for you. The task is to fill a dry bottle with rice and lift it up using only a pencil.

Have a go or challenge your friends, once you think you’ve cracked it (or given up) scroll down to see how we did it!

The Solution

Take the lid off the bottle and push the pencil half way into the rice. Take the pencil out again and push it back in, repeat this about 10 times. Eventually, when you pull the pencil to take it out, the bottle will lift up with it!

This occurs due to the force of friction acting on the pencil and holding it in place. When you first pour the rice into the bottle, it will arrange itself with lots of gaps but every time you insert the pencil you push the rice down making it more compact or dense. Some grains may even break or change shape under impact with your pencil. The more you do this, the greater the surface area of rice that comes into contact with the pencil. This gives a greater force of friction. Friction is a force of resistance between two objects when they  move past each other. The force is so strong at this point that it doesn’t allow the pencil to slip past the rice and so the rice (and the bottle) moves with the pencil as you lift it.

In the Real World…

This works in a similar way to quicksand. If you were to step onto quicksand, you would compact the particles, making them move closer together and lock around your foot, pulling you in. The friction makes it difficult for you to pull your foot out. Don’t worry too much though – quicksand is much denser than a human being so you wouldn’t be able to completely sink in it. As we learnt from our ketchup packet submarine and the oil and water experiment – less dense substances float above denser substances so you would stay above the surface of quicksand!

#TryThisTuesday: Cup Drop

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For the week’s science demonstration, you will need a metal mug or screw, a pencil and string.

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  1. Tie one end of your string onto the handle of the mug and the other to your bolt.
  2. Hold onto the screw and pick up your pencil with your other hand.
  3. Lift up the string with the pencil and hold it about half way along the string, on the same level as the screw, allowing the cup hang down.

What do you think will happen from this position if you let go off the screw?

You may think that the cup will simply fall to the floor due to the pull of gravity and the string will pull the screw along, leaving you holding a pencil mid-air.

In reality, nothing (hopefully) hits the floor. You are right in thinking, gravity wants to pull the cup down, but it also wants to pull the screw down too. As the cup begins to drop it pulls the string, pulling the screw in towards the pencil, as the screw is being pulled from two directions it ends up swinging towards them. As it has a bit of weight behind it, it builds up enough momentum to go around the pencil a few times, wrapping the string around it.

So now the string is wrapped around the pencil and the cup still hasn’t dropped. If you try to pull the screw now, you’ll see why. It’s difficult to move the string. This is due to the force of friction. Friction is a force that occurs between two objects, it is the resistance that occurs when they move over each other. As the string is wrapped around the pencil a few times, there is a larger area of string touching the pencil, so a greater force of friction. This keeps the string in place to stop it sliding off, allowing the cup to hit the floor.

Try this out with your family and friends, see if you they can guess it correctly!

#TryThisTuesday: Rock Candy

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This weeks Try This Tuesday takes a while, but you end up with a tasty treat!

You will need:

  • A wooden skewer or chopstick
  • Peg
  • 1 cup of water
  • 2-3 cups of sugar
  • A narrow glass or jar

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Clip the wooden skewer into the peg so that it hangs down inside the glass and is a couple of centimetres off the bottom.

Put the water into a pan and bring it to the boil. Pour about a quarter of a cup of the sugar into the boiling water and stir until it dissolves.

Keep adding more and more sugar, each time stirring it until it dissolves, until no more will dissolve. This might take quite a while!

When no more sugar will dissolve remove it from the heat and leave it to cool for about 20 minutes.

Pour the sugar solution into the glass or jar almost to the top. Then put your skewer back into the glass so it hangs down and doesn’t touch the sides.1st

Leave your glass in somewhere it won’t be disturbed. The sugar crystals will grow over 3-7 days. Once these have grown you can eat them!finished-product

The Science

By mixing the sugar and water together when they were really hot, you have created a super saturated solution. This means that the water contains much more sugar than in could in normal circumstances. As the water cools back down the sugar leaves the solution (mixture) and becomes sugar crystals again, forming on the skewer.

Supersaturated solutions are used in real life. In a sealed fizzy drink the drink is saturated (full) with carbon dioxide, as the carbon dioxide is put in using pressure. When you open the drink, the pressure of the carbon dioxide is decreased, which causes your drink to be supersaturated as there is much more carbon dioxide dissolved than there would be at normal pressure. The excess carbon dioxide is given off as bubbles.

#TryThisTuesday: Exploding Lunch Bag

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Today we are going to make an explosive lunch!

You will need

  • One small (sandwich size) zip-lock plastic bag
  • Bicarbonate of soda
  • Warm water
  • Vinegar
  • A tissue

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Do this experiment outside, or at least in the kitchen sink. Put about a quarter of a cup of warm water in the bag with half a cup of vinegar.

Put three teaspoons of the bicarbonate of soda into the middle of the tissue and fold it up into a little parcel.

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Partially zip the bag closed but leave a little space to add the bicarbonate of soda parcel in. Put the tissue parcel in the bag and quickly zip the bag completely closed.

Put the bag on the ground and step back. The bag will start to expand and hopefully pop!

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The Science

The bicarbonate of soda and the vinegar eventually mix together, the tissue just gives you enough time to get the bag shut. A reaction takes place between the alkaline bicarbonate of soda and the acidic vinegar, this is know as an acid-base reaction. The reaction produces carbon dioxide, which begins to fill the bag. After a while the bag can no longer hold any more gas so it pops!

The reactions between acids and alkalis are used lots in real life too. Farmers can treat acidic soil with alkaline lime fertilisers to neutralise the soil and allow plants to grow. It’s also a good way to treat a wasp sting; wasp stings are alkaline so you can treat them by putting vinegar on the sting.

#TryThisTuesday: Chicken Sounds from a Cup!

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This week we are going to make chicken sounds from a cup!

You will need:img_4715

  • plastic cup
  • string
  • paperclip
  • paper towel
  • scissors
  • water
  • pin

 

 

 

First put a hole in the top of your cup. We found it easiest to push a pin through and then make the hole larger with scissors.

Cut a piece of string that is about 20cm long and put it through the hole in the cup.

Tie the top end of string to the side of the paper clip.img_4716

Wet the paper towel. Hold the cup in one hand and wrap the paper towel around the string near the paper cup. Squeeze the string and pull down in sharp jerks to make the chicken noise!

The Science

Sound travels in waves, which cause particles to vibrate and causes the sound. The vibrations from the string would normally be almost silent without the cup.

When you add the cup it amplifies the sound and makes it much louder. This is because the cup is a solid object, and there are lots of closely squashed together particles in a solid object for the sound waves to hit and vibrate. The more vibrations the LOUDER the sound.

 

#TryThisTuesday: Milky Fireworks

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For this week’s experiment you will need to raid your fridge and kitchen cupboards to get some milk, food colouring and washing up liquid.

Pour some milk into a dish or bowl, this works better with full fat milk (we’ll tell you why later!). Add small drops of your food colouring wherever you like in the milk.

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Get some washing up liquid on the end of a spoon or cotton bud and gently tap the spots of food colouring with it. 20170509_143248

The food colouring should burst out into colourful stars and wavy shapes. This happens because the washing up liquid molecules have a hydrophobic tail, these means that they don’t like water so try to get away from it by seeking fat molecules. The milk (especially if it is full fat milk) contains lots of fat molecules. So the washing up liquid moves around in the milk seeking out this fat and takes the food colouring along with it, creating these funky patterns.

This is why we use washing up liquid to clean our dishes. The hydrophobic, fat-loving parts cling to grease and fat. The head of the washing up molecules are hydrophilic, meaning they love water. The heads cling to the water and the tails cling to the grease, this pulls the grease and dirt from your plates and washes them away with the water, giving you sparkly clean dishes.

 

#TryThisTuesday: Cork Balancing

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Today we’re challenging you to balance a cork on its round side, on the very end of your finger, whilst keeping your finger straight. 20161018_163129_resized

Could you manage it?

It’s quite tricky, but here’s a hint: two forks could help you out.

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Have you figured it out yet? Remember the cork must be balanced on your finger not the forks.

The solution is to stick the forks into either side of the cork. You should then be able to easily balance it on the end of your finger.

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There are two reasons this works. Firstly the forks add weight to the object you’re trying to balance. Because the ends of the forks hang below your finger, it lowers the centre of mass so that it sits underneath your finger, increasing the stability.

Secondly, adding the forks extends the object. By making it longer, the centre point is also stretched making it easier to locate so easier to balance the object. This is why tight-rope walkers often have long poles to help them balance.

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