Sunday, September 11, 2011

Gravity and Weight


Gravity is a force that pulls everything towards ear Gravity make it seems as if things always fall downwards. Gravity holds us onto earth and stops us fying off into space.

We carried out an experiment using the following material:

*stiff card

*pencil and crayons

*scissors

*small coins

*glue

*stick

Procedure

1. Draw 2 copies of a bear on stiff card ( 10cm from top to bottom and cut them out.

2. Decorate the shapes so that one is the back of the bear and the other is the front.

3. Stick small coins on the back of the paws of one copy and stick the undecorated side together with the drawing side.

4. Balance the bear's nose, hands downwards on the end of a pencil.

Observation
We observed if the bear balanced on the pencil.

Result

The bear did balance on the pencil because the weight of the coins made its nose the centre of gravity.





Friday, September 2, 2011

Young Scientists





….Water Displacement....
Are water levels affected by objects of various mass?

INTRODUCTION
Water displacement is simply when something (e.g. a block) is put into water and the water level rises. This is because the block is taking up space, and the water has to move somewhere, and the only place to go is up.

Required materials:
*Glass jar with a lid

*water
*Bucket
*Pen or pencil
*Journal to record results
Step-by-step procedures

1. Fill the bucket with water so it's about three-fourths full.

2. Make sure the jar has its lid attached. Place the jar into the water. What happens? Write it in your journal.

3. Now, slowly push the jar to the bottom of the bucket. Look at the level of water on the side of the bucket. What happens? Does the water level rise or fall? Record the result in your journal.

4. Remove the jar from the bucket and fill it completely with water. Secure the lid on the jar. Place the jar back into the bucket of water. Does the water level rise, fall, or stay the same? Record the results in your journal.

We placed different objects with different weights and recorded it.

Result: The sealed empty glass floated in the water and the water level remained the same until we pushed the jar to the bottom of the bucket. The water level increased and almost filled the bucket. Then we filled the empty glass jar with water and placed it into the water. The jar sank to the bottom almost instantly and the water level rose. So are water levels affected by objects of various mass...? YES!

Conclusion Before we filled the jar with water the weight of the water was heavier then the empty glass jar causing it to float. When we filled it with water it became heavier and sank causing the water to rise.