Science Assessment ~ Topics ~ Energy: Forms, Transformation, Transfer, and Conservation ~ Item NG078003 ~ Student Performance

A student uses a rubber band to shoot a toy car across a level floor. Imagine that no energy is transferred between the car and the floor or between the car and the air.

What happens to the total amount of energy in the system (car and rubber band) as the rubber band is released, and the car moves across the floor?

The total amount of energy in the system increases because the kinetic energy (motion energy) of the car increases, and the elastic potential energy of the rubber band stays the same.
The total amount of energy in the system increases because the increase in the kinetic energy (motion energy) of the car is more than the decrease in the elastic potential energy of the rubber band.
The total amount of energy in the system decreases because the increase in the kinetic energy (motion energy) of the car is less than the decrease in the elastic potential energy of the rubber band.
The total amount of energy in the system remains the same because the increase in the kinetic energy (motion energy) of the car is the same as the decrease in the elastic potential energy of the rubber band.

Distribution of responses
Answer Choice		Overall	Grades			Gender		Primary Language
		n = 3370	4–5 n = 0	6–8 n = 1705	9–12 n = 1665	Male n = 1526	Female n = 1737	English n = 3059	Other n = 196
A.	The total amount of energy in the system increases because the kinetic energy (motion energy) of the car increases, and the elastic potential energy of the rubber band stays the same.	25%	N/A	28%	21%	24%	26%	24%	25%
B.	The total amount of energy in the system increases because the increase in the kinetic energy (motion energy) of the car is more than the decrease in the elastic potential energy of the rubber band.	33%	N/A	34%	32%	29%	36%	33%	36%
C.	The total amount of energy in the system decreases because the increase in the kinetic energy (motion energy) of the car is less than the decrease in the elastic potential energy of the rubber band.	18%	N/A	20%	16%	19%	17%	18%	17%
D.	The total amount of energy in the system remains the same because the increase in the kinetic energy (motion energy) of the car is the same as the decrease in the elastic potential energy of the rubber band.	25%	N/A	18%	31%	28%	21%	25%	22%

Science Assessment

Item NG078003: After a rubber band is used to shoot a toy car across the floor, the total energy of the system will remain the same because the increase in the motion energy (kinetic energy) of the car is the same as the decrease in the elastic energy of the rubber band.