Original Project
Force and Motion
If a force acts on an object in the same direction as the direction of its motion, the object’s speed will con…
Item FM036003:
An object is moving forward. Then a force begins to push on the object from behind.
What will happen to the object's motion while this force acts? You can assume that the force of friction is so small that it will not affect the object’s motion and that there are no other forces acting on the object.
A. The object's speed will increase the entire time the force acts.
B. The object’s speed will stay the same the entire time the force acts.
C. The object’s speed will increase for a while and then stay the same.
D. The object’s speed will stay the same for a while and then increase.
- Distribution of Responses
- Students Responding Correctly
| Group | Correct | Total | Percent |
|---|---|---|---|
| Overall | 1451 | 3513 | 41% |
| Grades | |||
| 6–8 | 929 | 2232 | 42% |
| 9–12 | 516 | 1271 | 41% |
| Gender | |||
| Male | 717 | 1672 | 43% |
| Female | 712 | 1770 | 40% |
| Primary Language | |||
| English | 1315 | 3163 | 42% |
| Other | 107 | 279 | 38% |
- Disciplinary Core Ideas
- PS2.A The motion of an object is determined by the sum of the forces acting on it; if the total force on the object is not zero, its motion will change. The greater the mass of the object, the greater the force needed to achieve the same change in motion. For any given object, a larger force causes a larger change in motion.
PS2.A Newton's second law accurately predicts changes in the motion of macroscopic objects.