Key Idea: The amount of kinetic energy (motion energy) an object has depends on the speed and the mass of the object.
Students should know that:
- Kinetic energy is energy of motion and applies to the motion of atoms, molecules, or macroscopic objects.
- The kinetic energy of an object is related to both the speed and the mass of the object, and the amount of kinetic energy an object has can be determined from
these two factors alone.
- Any object that is moving has kinetic energy and the kinetic energy of an object that is not moving is zero.
- For objects that have the same mass, the object with the greatest speed has the greatest kinetic energy and the object with the lowest speed has the least
kinetic energy.
- For objects traveling at the same speed (greater than zero), the object with the greatest mass has the greatest kinetic energy and the object with the least
mass has the least kinetic energy.
Boundaries:
- Assessment items use the phrase “kinetic energy (motion energy)” to avoid confusing students who are not familiar with the phrase “kinetic energy.”
- Assessment items expect students to compare relative speeds and masses to determine relative amounts of kinetic energy. Students are not expected to
calculate the exact amount of kinetic energy.
- Assessment items use either metric or non-metric units of speed (e.g. meters per second or miles per hour) as described in CCSS for mathematics.
- Students at this level are not expected to know the difference between “weight” and “mass.” All of the contexts used in the assessment items are ones
where “mass” and “weight” are proportional to each other. When two objects are compared, they are in the same gravitational system.
- This idea refers to motion with respect to the surface of the earth. An object is considered to be “not moving” if its position with respect to a point on
the surface of the earth is not changing.
- Items may show objects moving in a straight line, vibrating back and forth, or rotating. In all cases, students are expected to know only that the amount
of energy of motion an object has depends on its speed and mass. In items, comparisons will be made between objects moving in the same manner (i.e., both
rotating) and with the same distribution of mass from the origin.
Percent of students answering correctly (click on the item ID number to view the item and additional data)
Item ID
Number |
Knowledge Being Assessed |
Grades
4–5 |
Grades
6–8 |
Grades
9–12 |
Select This Item for My Item Bank |
EG004005
|
A car has the most motion energy when it is traveling at the highest speed.
| 80% | 67% |
72% | 
|
EG012003
|
A ball has more motion energy than a person when the ball is moving and the person is not moving.
| 75% | 61% |
70% | |
EG076002
|
A basket ball has more motion energy than a boy when the ball is moving through the air and the boy is standing still.
| 58% | 65% |
73% | |
EG001007
|
For two balls that have the same mass, the ball that is rolling faster has more motion energy.
| 74% | 63% |
66% | |
EG005004
|
Increasing the speed of an object increases its motion energy.
| 60% | 57% |
72% | |
EG008004
|
A ball has motion energy only when it is moving.
| 58% | 60% |
69% | |
EG081005
|
Two objects that are moving at the same speed must have different masses in order to have different amounts of motion energy.
| 55% | 57% |
71% | |
EG001008
|
For two balls that have the same mass, the ball that is rolling faster has more motion energy.
| 71% | 55% |
64% | |
EG003004
|
Two children that have the same mass and are sledding at the same speed have the same amount of motion energy.
| 56% | 62% |
59% | |
EG007003
|
The motion energy of an object depends on the speed and mass of the object.
| 49% | 57% |
68% | |
EG010004
|
For two objects that weigh the same, the object with more motion energy is moving faster.
| N/A | 55% |
64% | |
EG003005
|
Two children that have the same mass and are sledding at the same speed have the same amount of motion energy.
| 46% | 54% |
66% | |
EG023003
|
Both a ball that is thrown and a ball that is dropped have motion energy while they are moving.
| 51% | 58% |
58% | |
EG081006
|
Two objects that are moving at the same speed must have different masses in order to have different amounts of motion energy.
| 41% | 54% |
65% | |
EG081004
|
Two objects that are moving at the same speed must have different masses in order to have different amounts of motion energy.
| 48% | 53% |
62% | |
EG077002
|
When comparing two identical cars, the car that has more motion energy is moving faster than the car that has less motion energy.
| N/A | 53% |
56% | |
EG002003
|
For two pinecones falling at the same speed, the pinecone with more mass has more motion energy.
| 43% | 50% |
53% | |
EG009004
|
For two objects that are traveling at the same speed, the object with more motion energy weighs more.
| N/A | 37% |
51% | |
EG092002
|
The motion energy of an object depends on the speed of the object but not the direction the object is moving.
| 41% | 36% |
47% | |
EG079002
|
When comparing two runners with different amounts of motion energy, the only way to know which one weighs more is to also know how fast each is running.
| N/A | 32% |
48% | |
EG078002
|
When comparing two cars traveling at the same speed, the car that has more motion energy weighs more than the car that has less motion energy.
| N/A | 35% |
41% | |
EG024002
|
In order to know which of two objects weighs more, you need to know the speed of each object in addition to the motion energy.
| N/A | 29% |
32% | |
EG080002
|
When comparing two bike riders with different amounts of motion energy, the only way to know which one is riding faster is to also know the weight (mass) of each.
| N/A | 21% |
37% | |
RG177001
|
When a girl and skateboard move at the same speed, the girl has more kinetic energy because the she weighs more than the skateboard.
| 20% | 20% |
29% | |
EG025002
|
In order to know which of two objects is moving faster, you need to know the weight (mass) of each object in addition to the motion energy.
| N/A | 18% |
29% | |
EG006006
|
When a person is riding a bike, the person has more motion energy than the bike because the person weighs more than the bike.
| 15% | 21% |
29% | |
Frequency of selecting a misconception
Misconception
ID Number |
Student Misconception |
Grades
4–5 |
Grades
6–8 |
Grades
9–12 |
EGM011 |
The motion energy of an object does not depend on the mass of the object (Herrmann-Abell & DeBoer, 2009, 2010). | 31% | 39% |
38% |
EGM017 |
For two objects traveling at the same speed, the heavier one will have less kinetic energy (AAAS Project 2061, n.d.). Some students think that heavy objects are weighted down and don't have much energy. | 23% | 23% |
21% |
EGM048 |
Living things give inanimate objects energy by carrying or pushing them. For example, a person gives a bike energy by riding it or a bird give a stick energy by carrying it (Herrmann-Abell & DeBoer, 2010). | 26% | 22% |
16% |
EGM054 |
When comparing two objects, the object that has more motion energy, weighs more (has more mass) regardless of the speed of the two objects (AAAS Project 2061, n.d.). | 9% | 21% |
17% |
EGM052 |
The motion energy of an object depends on the direction the object is traveling (AAAS Project 2061, n.d.). | 21% | 18% |
14% |
EGM055 |
The motion energy of an object depends on its size (AAAS Project 2061, n.d.). | 21% | 19% |
13% |
EGM057 |
The motion energy of an object depends on the material an object is made out of (AAAS Project 2061, n.d.). | 21% | 15% |
14% |
EGM016 |
Objects that are falling do not have motion energy (Herrmann-Abell & DeBoer, 2010). For example, a dropped object doesn’t have motion energy because gravity is just pulling it down. | 21% | 14% |
13% |
EGM012 |
The motion energy of an object does not depend on speed (the motion energy of an object does not increase as the speed increases) (Kruger, 1990). | 14% | 15% |
12% |
EGM073 |
The faster an object moves the less kinetic energy it has. For two objects with the same mass, the one that is moving faster will have less kinetic energy. | 13% | 12% |
10% |
EGM056 |
The motion energy of an object depends on its shape (AAAS Project 2061, n.d.). | 10% | 13% |
9% |
EGM001 |
Energy is associated mainly with human beings, not inanimate objects (Finegold & Trumper, 1989; Kruger, 1990; Kruger, Palacino, & Summers, 1992; Leggett, 2003; Liu & Tang, 2004; Solomon, 1983; Stead, 1980; Trumper, 1990, 1993, 1997a, 1997b; Trumper & Gorsky, 1993; Watts, 1983). | 18% | 11% |
8% |
EGM013 |
Energy is not associated with motion. For example, a toy with a spring has energy only until the spring resumes its former shape and a rock falling of a cliff does not have energy (Kruger, 1990). | 4% | 6% |
7% |
Frequency of selecting a misconception was calculated by dividing the total number of times a misconception was chosen by the number of times it could have been chosen, averaged over the number of students answering the questions within this particular idea.
