# Physical science

## paint brush (made from horse hair)

sound: Prepare in advance a cutting board and a paint brush made from wood and horse hair. Say: let's listen to what sound the paint brush will make. Remember that soundwaves are created when some energy is applied to the object. Then molecules of the medium start moving pushing other molecules, making them vibrate. That’s how the sound is created. Let's listen to the sound that the paint brush will create. Take the tool in your right hand and let it drop on the cutting board. Say: Pow! can you hear the sound? It is loud and bangy! Let's do it again! Put the paint brush in the baby's right hand and help the baby strike the brush against the surface of the cutting board. Say: bang, bang, bang!

elastisity and plasticity: we know that elasticity is ability of the object to retain its size and shape after removing the force that is applied. If the object does not deform, it is considered very elastic. Let us see if hair of this paint brush is elastic. We will make an experiment. We will bend the hair and see if it will deform. What do you think will happen to the hair? I think it will not remain bent. Now let's conduct an experiment. Take 1 paintbrush and bend the hair on it with your right hand. Help baby to do the same. Observe the hair. Say: I see that the hair did not get deformed, it returns to its original shape. Hence we can conclude that this material is elastic. Remember, that plasticity can be tested in the same way. If after bending the object retains the new form without rupturing or breaking, it means it is very plastic. The hair is not plastic, because it regains its previous form.

Hardness. Say: I wonder if the material the paint brush is made of is hard. When we say the object is hard, we mean that when I scratch it with another sharp object there is no sign left on it. It is very difficult to leave traces on it. If the object is hard it means it is resistant to permanent shape changes. Do you think the paint brush is hard? Let's make a hypothesis. I think it is hard. Let us conduct an experiment in order to prove or disprove out hypothesis. We will need a coin for that. Take the paint brush in the left hand and the coin in the right. Make sure your hands are in front of the baby's face so he can see well what is happening. Say: let's scratch the wooden part of the brush with the coin. Do that. Say: let's observe now. What do you see? Do you see any scretches left on the surface of the brush? I see no scretches. It means the brush has a hard surface.

Let’s explore if the brush is waterproof and absorbent. A material is waterproof when it repels liquids. What do you think about the paint brush? Is it waterproof? I think it is not. Now let's make an experiment to prove our hypothesis. Take a large pot. Put a jar/cup into it. Put the brush on top of the jar/cup so its hair will cover the opening like a lead. Say: let’s observe. Poor water on the hair part. Say: the paint brush is not waterproof; water can go through it into the jar/cup. What is absorbancy then? It is ability of any material to soak up the water, right? What do you see happened to the brush? See it soaked up some water. Let’s squeeze the brush now to see how much water got into it. Squeeze it. Say: see, there is some water coming out of it. The hair of the brush is absorbent.

Glossy/mat: Say: The (object) is shiny/glossy/mat. (glossy - reflects the light, mat - absorbs the light)

Brittleness: DO you think the (object) is fragile? Make an assumption. The characteristic for fragility is brittleness. We will drop the(object) from up to the ground and observe if it breaks. Let’s do an experiment. (Take an (object) and drop it from stretched high hand). Say: look at the (object), it did not break at all! It is not brittle. Or it broke and it is brittle.

Magnetic: Let’s see if it is magnetic. We will get a magnet and put it close to the (object). See: the (object) is on the same place. It does not move so it is not magnetic.

Transparent, translucent, opaque: Hold the (object) in your left hand in front of the baby and say: (baby's name),do you think (object) is see-through? Le's make a hypothesis. I thinks it is. Now we have to make an experiment to prove or disprove it. We will need a dark room and a flashlight. Make the room darker or go to the dark room. Place the object in the left hand and the flashlight in the right hand. Switch the flashlight on and say: let's observe if the light goes through the (object). Say: I can see some light passing through the leaf. It is translucent. (If your leaf is thick – you cant and then the leaf is opaque).

Fluid.Now we will see if the (object) is fluid. My hypothesis is that it is not. We will conduct an experiment in order to check it out. Hold the (object) in your right hand with two fingers if possible. Say: Look! I am holding it and it does not change its shape and does not move at all. It does not flow.

Soluble: Let’s see if it is soluble. What do you think, is it soluble? I guess it is not. Let's again make an experiment and check it out. We will need some water. Take an empty bowl, pour some water into it. Put the leaf into water again. Say: look the leaf does not dissolve in the water. It remains as it is. It means it is not soluble.

Insulator: If we put a lot of leaves together in a pile, they will be a good insulator. They will keep warmth inside.

Burn: (object) contains oxygen molecules and can burn with high temperatures. (explain about your object)

Let’s check if the paint brush is made of a ductile material. Let us try to stretch it and observe if it becomes a wire.If it does, then it is ductile. Start stretching. Say: see, the paint brush is very hard to stretch! It is not stretchable at all. Hence It is not ductile.

Our (object) smells so fresh and nice! Or describe how it smells

If you've found a typo, mistake, or incorrect information, please let us know!