This video is a great example of an experiment with energy. The scientist, Professor Pipette, invites the students to observe the transfer of energy. She gives an example of energy transfer by juggling, Explaining that objects have energy, hands have energy, and even the air around the objects have energy. in order for there to be movement, there must be energy. When an object stops moving, does that mean that the energy is destroyed? no. when there isn’t a movement, energy is not destroyed it’s just changed form from one form to another.
She sets up the experiment with energy transfer by listing the items needed. First, she sets up a low ramp. Next, add some more blocks to increase the height of the ramp. Finally, she shows some items to transfer energy, a tennis ball, an irregular-shaped rock, and a marble.
Energy Transfer Using a Low Ramp
She then rolls the tennis ball down a low ramp. She provides a question and encourages the students to state their hypotheses. She asks if the ball will have enough energy by rolling it down the ramp to push over the block. She allows the ball to roll down the low ramp, hitting the block at the end, but not knocking it over. She demonstrates making observations by saying “I noticed it rolled slowly, but the energy transferred by the ball was enough to move the block.” She then explains that even though the ball stopped, the energy was not destroyed.
Next, she attempts to roll the rock down the ramp. It barely made it to the end of the ramp before coming to a stop. She explains that the rock moved slowly down the ramp and had much less force. She connects the idea of the rock’s lack of speed to its lack of energy. She also encourages kids to question why the rock could not roll down the ramp. It is because the rock is not around so this makes it harder to gain more speed when rolling down the ramp.
Lastly, on the low ramp, she uses a small marble. It is heavier than the ball but smaller. It is also round unlike the rock. She again asks students to hypothesize if the object will have enough energy to affect the block. She observes the marble move faster, most likely because it is heavier, and transfers more energy to the block.
Using a Higher Ramp
In order to make an object go faster and have more energy, she increases the height of the ramp. Now that the ramp is higher, let’s see if the tennis ball will roll faster. When she places the ball at the top of the ramp it should have stored energy due to the force of gravity acting on it. When the ball is released that stored energy is changed into motion energy. Increasing the height of the ramp also increases the amount of stored energy in the ball. If the ball is released from a higher starting point it rolls faster and farther.
Although she used a ball, a marble, and a rock today, transfers of energy happen all around you. Next time you see somebody skateboarding down a ramp, take a look at the height. The taller the ramp the faster the person’s going to go. The faster an object moves the more energy it possesses and the more energy is able to be transferred.
The experiment done in this video could easily be replicated and modified in the classroom. You could use this video as an introduction to the experiment. I would create simple worksheets or other guiding objects that help students work through the scientific method while they conduct this experiment. Students could make predictions and hypotheses, test their ideas, and record data.
Aligned with Next Generation Science Standards: 4-PS3-1 Use evidence to construct an explanation relating the speed of an object to the energy of that object. Assessment does not include quantitative measures of changes in the speed of an object or on any precise or quantitative definition of energy.
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