Wednesday 18 November 2009

Cars and Friction

Wednesday, November 18th, 2009
We got some new cars and a new car mat in our classroom. We love playing with them. Today we decided to try out some science and maths activities with them. Teacher made a ramp. We had to guess how far the car would travel when it came off the end of the ramp. Then we measured the distance it travelled using lollipop sticks. First of all we tried it from the ramp onto the floor. This distance measured 17 lollipop sticks.
Next we tried the car mat. The car came speeding down the ramp, but slowed down when it came to the car mat. We guessed that the fluff on the surface of the mat slows down the wheels of the car. This is because of a force called friction between the wheels and the mat. The car only travelled 4 lollipop sticks on this surface.We tried our jigsaw mats next. On the smooth side the car travelled 3 lollipop sticks, and on the rough side the car travelled 3 and 1/2 lollipop sticks before it stopped. We found this result a little surprising but we think that the car bounces over the rough side easier than the smooth side (less friction). The last time we tried the car it was on a rug. The car didn't travel far on this rug at all. It went only 2 and 1/2 lollipop sticks. This is because the rug was very soft and it slowed the car down a lot.We were careful to make this a fair test. The ramp stayed the same all the time and the car was not given any push to start. Each time we measured the distance we did it from the bottom of the ramp to where the car stopped. We loved this investigation, and we can't wait to try it at home ourselves.

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