Testing the Effects of Rubber Band Energy

 Standard vehicle (per group of 3)  3 rubber bands connected (per group of 3)  13 feet/4m of adding machine tape (per group of 3)  3 each self stick red, blue, and green dots (per group of 3)  Masking tape (per group of 3)

 You will predict and investigate how variation in rubber band energy affects the distance your vehicle travels.  You will record your results.  You will share results and identify patterns.  You will discuss the relationship between the number of turns of the rubber band around the axle and the distance your vehicles travel.

 The rubber band has the potential to move the vehicle because of its stored energy.  However, there is no motion until students release the wound rubber band.  As the number of turns on the rubber band increases, so does the energy stored in the rubber band.  As the stored energy increases, so does the initial speed acquired by the axle driven vehicle and the distance it can travel.  The faster the vehicle moves, the more energy of motion it has.

 When the rubber band is completely unwound, it has no more energy to give the vehicle.  However, the vehicle continues to roll while friction slows it down.  Friction opposes the vehicle’s forward motion as it changes the energy of motion into the energy of heat.  Friction also acts on the vehicle while it speeds up, but the rubber band force overwhelms friction during this part of the motion.

 You will be using 2, 4, and 8 turns of the rubber band in this investigation.  There is no relationship between the number of turns and the distance the vehicle travels.  Therefore, 4 turns on the rubber band does not make the vehicle move twice as far as 2 turns.

 You will be making predictions and collecting data to investigate how the number of turns of the rubber band on the axle affects the distance your vehicle travels.  Get in groups of 3.  Collect adding machine tape, standard vehicle, 3 red dots, 3 blue dots, and 3 green dots per group.

 Collect materials.  Do not disassemble your standard vehicle.  Display adding machine strips and tape on wall with one above the other.  What differences do you see in each of these strips?  What patterns do you see in each of these strips?  Compare the predicted stopping point to the actual stopping point of the vehicle.

 Where does the energy to wind the rubber band come from?  From our muscles  Where does the energy to move the vehicle come from?  Rubber band  How do you store energy in the rubber band?  Wind rubber band around axel  How do you release the energy stored in the rubber band?  Let go of vehicle  What happens when the stored energy in the rubber band is released?  Vehicle gains energy of motion, axle turns  How does the number of turns on the rubber band affect the distance the vehicle travels?  More energy stored means farther distance  Why was it important to keep the number of turns the same for all groups in the class?  To make fair comparisons  What would happen if the number of turns was only 1?  What would happen if the number of turns was 10?

 Measure the distance the vehicle traveled when wound 2, 4, and 8 times. Then, graph these results.  Challenge groups to hold a race and make their vehicles go as far as possible.  Have students use masking tape to mare a race track that has angles. Students race on the track. The vehicle must remain inside the racing lane. Before they race, have them predict for each turn, how many turns of the rubber band are needed to move their vehicles the given distance.