force and motion

In the previous blog post, How To Build a Ramp, I shared some of the children’s learning about force and motion. The Kindergarteners are a community of builders. From large to small building, there has been an ongoing interest in various kinds of structures and simple machines. The children often use hollow blocks and pieces of recycled wood to construct ramps. With the integration of various materials, such as pieces of sandpaper and marbles, they have been exploring force and motion.

The young scientists have been using an assortment of solid balls (spheres) to investigate the influence of weight and slope on the distance and speed a sphere will travel. Through our calendar work this month, we have been learning about different kinds of measurement and specific tools. We used a balance scale to compare the weight of the spheres. Using this information, the children predicted how far each sphere would travel. To ensure no other factors would influence our findings, we used a ramp with a consistent slope and kept the location on the rug the same - the friction caused by our oval rug did not change.

IM placed a small block on the rug for each prediction. The children then tested their ideas by rolling the spheres down the ramp. The slope of the ramp and the force of gravity ensured the spheres were pulled down the ramp. Using a yardstick, we measured the distance (in inches) traveled by each sphere. For some, the distance was so great, that we needed to add numbers together to get the total of inches traveled. 

Our science conversation was rich with number work; adding 36 and 16 to determine one distance and 88 and 5 for another! Some of the children used unifix cubes to count the total - grouping the ones into trains of ten and counting by tens before adding on their ones. CM had a different strategy; the 100's chart! She started at 88 and then counted on the additional 5 inches traveled by the heaviest sphere - a total of 93 inches. 

In the below photographs, OM compares the weight of each sphere while TW records his findings and thoughts from their peers. The heaviest sphere is the solid rubber bouncy ball, next is the golf ball, followed by the small bouncy ball, and finally the marbles. One marble - the green one - is surprisingly heavier than the other marbles.

 

The children predict the heaviest sphere will travel the farthest - because the weight of each sphere pulls it down the ramp. We measure, count, and record. Their predictions are correct!

 

 

 

 

But, what would happen if we tested two spheres of the same weight on two ramps with different slopes? Which sphere will travel farther?

The children predict that the ball rolling down the ramp with more of a slope - or one end of the ramp higher than the end of the other ramp - will travel faster and farther.

TW later explains - with his body and his ramp diagram - that if you want a ball to travel slowly you need less of a slope. He moves between showing different slopes with his outstretched arm to recording his thoughts on large chart paper. His peers actively listen to his ideas and construct the ramp next to him.