Friday, February 17, 2012

Simple Machines

Learning about simple machines gives your child a little insight into engineering. There are six types of simple machines.

*A lever is a simple mechanism like a board or a beam that rotates around a fulcrum.

*Wheel and axle is a simple mechanism that consists of two connected wheels, which rotate around the same axle.
*An inclined plane has no moving parts. Chutes, ramps, slides, and blades are examples of inclined planes.

*A wedge is an inclined plane that is used for lifting, holding, or separating objects.

*A pulley is a simple machine that uses grooved wheels and a rope to raise, lower, or move a load.

*A screw is a simple machine that holds things together.

Help your child execute experiments with each simple machine.

Here are two to get your started:

Messages on a Pulley

A PULLEY lets us change the direction of the force we use to do work.

Question: Can you use a pulley to help you send messages across a room?

Materials: 2 thread spools, 40 feet of string, 2 round pencils, paperclips, message

1. Put the pencils through the thread spool centers. Tie the ends of the string together to make a loop. Have one person hold the ends of one pencil (allowing the spool to turn freely. Have one person hold the other spool. Wrap the string around the spools to create a pulley system.
2. Write a message; attach it to the pulley with a paper clip. Have a third person pull the string to move the message.
1. Did you message travel across the classroom by pulley?
2. Is that what you thought would happen?
3. What did you learn?

Count the Turns
A SCREW is used to hold things together. It has a line that goes around it that is called THREAD (actually a twisting inclined plane).

Question: What type of screw takes more turns to go into a block of wood - one with more or less thread?
Materials: Wood block, same size screws with different sized threads, screwdriver, and masking tape

1. Wrap a screw driver handle with a piece of masking tape. Make a mark on the tape. YOU WILL COUNT ONE TURN EACH TIME THE MARK COMES BACK TO THE PLACE IT STARTED.
2. Place the screwdriver into the slot of one screw. Watch where the mark is and start turning the screw to the right.
3. Count how many turns it takes to get the screw all the way into the wood.
4. Repeat for the other screw or screws.

1. Which screw took more turns to go all the way into the wood?
2. Is that what you thought would happen?
3. What did you learn?

No comments:

Post a Comment