# Tutor Information

## Great Artists - Durer (DER)

Durer was fascinated by detail in all aspects of his work-- in oil painting, portrait drawing, water colors, and wood cuts. Of all forms of printmaking, woodcuts are the most ancient.

Tutors, I made an executive decision to forego the wood for this project. We will be using foam, cookie cutters and blocks. I have too many fears of smashed fingers with a bunch of kids using hammers. I will also have apples and potatoes available if you would like to let the students experiment with them.

## Science Experiments - Van Cleave's # 130 Stretch and # 132 Spurt

Here we go with OB/GYN Week ( per Cindy Amster)

130 - Stretch

Purpose:

To demonstrate the effect of a tension force.

Materials:

Balloon

Marking pen

Procedure:

- Draw a square on a deflated balloon ( this will be done beforehand).

- Divide the square into three sections ( completed beforehand).

- Use marking pen to color the two outer sections on the square ( beforehand).

- Inflate the balloon and observe markings.

- Deflate the balloon and observe the markings again.

Results:

The square spreads out in all directions when the balloon is inflated. If the balloon has not been inflated too much, it will recover its original shape and size when deflated.

Why?

The rubber molecules of the balloon are being pulled apart by the pressure of the air inside. Parts of the balloon stretch more than others, causing a change in the shape of the diagram drawn on the rubber. Tension is a stretching or pulling-apart force. If the force is not too great, rocks with elastic properties like the balloon will recover their original shape and size when the force is removed. If the force is too strong, the rocks cannot remain together, and they break apart -- as the balloon would if you continued to inflate it with air. When there is an earthquake, the rocks in the Earth's crust are pushed apart by this force.

132 - Spurt

Purpose:

To demonstrate what causes magma (liquid rock) to move.

Materials:

1/2 empty tube of toothpaste

Procedure: Completed by Director

- Hold the tube of toothpaste in your hands.

- With the cap screwed on tight, press against the tube with your thumbs and fingers.

- Move your fingers and press in different places on the tube.

Results:

The paste in the tube moves out from under your fingers. Toothpaste bulges around the sides of your fingers.

Why?

Liquid rock inside the earth is called magma. Pressure on pools of magma deep within the Earth forces the molten rock toward the surface. Magma cools and hardens as it rises toward the surface. The liquid moves into the closest open space as did the toothpaste when it squeezed between and around the spaces formed by your fingers. Magma that moves up vertically into cracks in the crust and hardens is called a dike. When magma moves horizontally between rock layers, the solid, thin sheet of rock formed is called a sill. This horizontal movement of magma can also form a pool of liquid. This hardened dome-shaped pool is called a laccolith. As the laccolith forms, the layers of rock above it are pushed up, just as the toothpaste was pulled up the tube.