Thursday, October 21, 2010

From the desks of Isaiah Elijah and Hannah

So we started our unit on motion this week. And this weeks lesson were all about Newton's laws, and velocity. Check out this cute experiments we did. Which will win the chicken or the clam? If we roll the two cans down a slop at the same time which can will reach the finish line first? The chicken or the clam?

On your mark, get set, go!

And the winner is.....the chicken.

The chicken soup wins, for a very simple reason. Imagine that the cans are transparent, so you can see what does on inside the cans as they roll down the ramp. Which one has just the can rolling down the ramp, and which has the entire contents locked together as it rolls? The can of the chicken soup will rotate around the soup itself, while the clam chowder acts as a solid cylinder and rotates together. So the inertial mass of the clam is much greater than the inertial mass of the soup, even though the cans weigh the same
Ok this one was super fun. Get a glass, a ball that is bigger than the opening of a toilet paper roll but smaller than the opening of the glass and a pie plate. Set it up as shown and then hit the rim of the pit plate.

TA DA the ball falls into the cup.

We got brave and did it with an egg.

TA DA it worked with the egg in tact.

Elijah had to double check the egg was ok.

This experiment is all about inertia. The force of your hand got the pie plate moving. The friction between the book and the tube causes the tube to move. The ball, which has a decent amount of weight, which means a decent amount of inertia, is not effected much by the moving tube. The ball, thanks to gravity, falls straight down and, hopefully, into the cup.

This is like the old trick of removing the table cloth and all the dishes stay on the table. My kids so wanted to try that so we did.

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