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 FM011005: The speed of a sailboat will continue to increase the entire time the force of the wind pushing it forward is greater than the force of the water slowing it down.
In the drawing below, the arrows labeled WIND and WATER represent forces acting on a sailboat during a certain period of time. During this period of time, the force of the wind on the sailboat is stronger than the force of the water on the sailboat. The directions of the arrows show the directions of the forces, and the lengths of the arrows represent the strengths of the forces.
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Which statement describes the sailboat's motion while these forces are acting?
- The sailboat will speed up for a short time and then move at constant speed.
- The sailboat will speed up for a short time and then slow down.
- The sailboat will move at constant speed the entire time.
- The sailboat will speed up the entire time.
- Distribution of Responses
- Students Responding Correctly
| Group | Correct | Total | Percent |
|---|---|---|---|
| Overall | 281 | 1713 | 16% |
| Grades | |||
| 6–8 | 195 | 1100 | 18% |
| 9–12 | 86 | 613 | 14% |
| Gender | |||
| Male | 161 | 839 | 19% |
| Female | 116 | 849 | 14% |
| Primary Language | |||
| English | 265 | 1578 | 17% |
| Other | 15 | 99 | 15% |
- 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.