In Newton's Third Law of Motion, for every action, there is an equal and opposite reaction, which means that forces always come in pairs.
Let's analyze the options given:
A) Kelly pushes on the rock, and the rock pushes on Earth.
- This is not a valid force pair as it misrepresents the interactions between Kelly, the rock, and the Earth.
B) Earth pulls on Kelly, and Kelly pulls on Earth.
- This is a correct force pair. The gravitational force is mutual between Earth and Kelly; hence it follows Newton's Third Law.
C) The rock pushes on Earth, and Earth pulls on the rock.
- This is a valid force pair. The forces involved are the gravitational force exerted by the rock on Earth and the equal and opposite force exerted by Earth on the rock.
D) Kelly pushes on the rock, and the rock pushes on Kelly.
- This is also a correct force pair. When Kelly exerts a force on the rock, the rock exerts an equal and opposite force back on Kelly.
Based on this analysis, the correct answers are:
B, C, and D.
1 answer