Newton's Third Law
Grade 8 · Science · Forces and Motion · Kentucky, USA
Lesson Summary
For every action there is an equal and opposite reaction.
Explanation
Newton's third law states that forces always come in pairs. When you push on a wall, the wall pushes back on you with the same amount of force in the opposite direction. When a rocket pushes exhaust gases downward, the gases push the rocket upward. These action-reaction pairs act on different objects, which is why they do not cancel each other out. This law explains how rockets fly, how boats move through water, and how you walk on the ground.
Practice Questions
Q1: When you jump, you push down on the ground. What is the reaction force?
Answer: The ground pushes up on you with an equal force, which is what launches you into the air.
Q2: How does Newton's third law explain how a rocket moves in space?
Answer: The rocket pushes hot gases out the back (action), and the gases push the rocket forward (reaction).
Q3: If you push a friend on roller skates, why do you also move backward?
Answer: Because when you push your friend (action), your friend pushes you back (reaction) with an equal force in the opposite direction.
People Also Ask
What is Newton's Third Law in Grade 8 Science?+
Newton's Third Law is a lesson in the Forces and Motion chapter of Grade 8 Science. It is part of the Kentucky, USA school curriculum and covers key concepts that students need to understand at this level.
What grade level covers Newton's Third Law?+
Newton's Third Law is taught in Grade 8 as part of the Science curriculum in Kentucky, USA.
How can I help my child with Forces and Motion in Science?+
Start with the lesson summary and explanation on this page. Practice the questions provided, then use TutorTom for personalized, step-by-step help with Forces and Motion topics.