In order for children to understand natural occurrences in our world, they first must understand how matter moves. The forces addressed in this unit have been strategically chosen to support students’ learning about natural disasters and occurrences. Buildup and release of stress and pressure is what fuels volcanic eruptions and earthquakes; friction causes some earthquakes; heat energy moves the water cycle, thunder storms, and hurricanes; and convection plays a big part in thunderstorms and hurricanes, and causes cold heavy tectonic plates to sink into the warmer viscous mantle. The lessons in this portion of the unit should be the foundation for learning.
State Changes
Heat is a type of energy and causes state changes in matter. When a solid is heated, energy in the form of heat raises the temperature of the solid causing the molecules to vibrate more quickly. The increased motion of the molecules causes them to break out of the pattern and eventually melt into a liquid. Upon heating the liquid further, the molecules move even more rapidly and the liquid begins to go through convection. The hottest liquid collects on the top and the quickly moving molecules escape in the form of gas. (Abruscato, 2001)
Stress and Pressure
In second grade, many crayons fall victim to children with less than perfect fine motor skills and crack under the pressure. When enough force is applied to the crayon, it can no longer support the pressure and snaps at its weakest point. Solid matter can be bent to a certain point but given enough stress it will break.
Friction
Newton’s first law of motion states that “An object in motion will remain in motion unless a force acts upon it to stop or change it.” (Trumbauer, 2008) If you were to putt a golf ball with a club and put it into motion and it did not hit anything, would it keep going? Of course not! The friction of the grass, the air and other environmental factors against the golf ball would slow it to a stop. Friction occurs when the surface of two objects move over one another, causing it to be a little more difficult for the object in motion to move. (Trumbauer, 2008)
Scope and Sequence
Day 1- Think and discuss- Put a matchbox car flat on a table and ask the children why it will not move. Then allow children to work in groups to list things that move, and what makes them move.
Day 2- Model the evaporation and condensation of water. Focus on the force that makes the water move.
Day 3- Read, or show the United Streaming video of The Magic School Bus Wet All over: a Book about the Water Cycle (see Student Resource list for more information).
Day 4- Investigatory experiment: Break, Bounce, or Deform? -- Children can be allowed to manipulate different types of matter to discover how it reacts when it is acted upon by an outside force. (this lesson is described in detail in the lesson plan titled Break, Bounce, or Deform?).
