Science
Week – 4th Class
Air
Pressure Experiment 1
We put a scrunched up, dry piece
of paper in a cup. We pushed the cup, open side down, into a sink full of
water. We took care not to let any air bubbles come out. When we lifted the cup
back out of the sink, the paper was still dry. We learned that the air
pressure, inside the cup, did not allow any water to get in. You can read more
details in the report below.
Air Pressure Experiment 2
We filled a cup all the way to the
top. We placed a piece of card on top of the cup so that it was touching the
surface of the water. We then slowly turned the cup upside down. The surface
tension of the water made a seal with the cardboard. Also, the air pressure
under the card held it up. For these reasons the card did not fall off and the
water did not flow out… at first. We also learned that if somebody pushes the
card it will fall off. The teacher was not cross as it was only a bit of craic J!
Column Construction
We practiced making columns from
paper. We learned that cylindrical columns are stronger than triangular prisms
or rectangular prisms. This is because the cylider shares the weigth equally
around all parts of the column. With the other shapes, a lot of the weight
rested on the corners, causing them to fold and collapse.
Bridge Construction
We looked at pictures of famous
bridges around the world. We discussed the features that allowed these bridges
to stand up even though they spanned long distances. We made our own bridges
using play dough, cocktail sausage sticks, barbecue skewers and straws. Each
bridge included columns, struts and reinforcement to allow it to stay standing
and to carry a load. Children placed a full water bottle on the bridge to show
that it was strong.
