Forces, the way Newton described them, change motion.
So when you throw a tennis ball against a wall, the tennis ball obviously applies a force to the wall.
What's less obvious is that the wall applied a force to the tennis ball. Did the motion of the ball change? Yes it did. What caused it? The wall.
So, using Newton's terms, the wall applied a force to the ball.
Turns out, the wall applies the exact same amount of force back as the ball applied forward.
*EDIT: The comments below are excellent expansions. The wall doesn't seem to move, but there are vibrations throughout the wall (and so on) that account for that force. And yes, many other forces are acting on the wall.
EXPLAIN IT TO ME LIKE I'M 10: Maybe it's better to say "forces affect inertia - they can help or hurt it."
napncrash t1_iugnia1 wrote
Reply to ELI5: Newton's third law by AppropriateFeeling44
Forces, the way Newton described them, change motion.
So when you throw a tennis ball against a wall, the tennis ball obviously applies a force to the wall.
What's less obvious is that the wall applied a force to the tennis ball. Did the motion of the ball change? Yes it did. What caused it? The wall. So, using Newton's terms, the wall applied a force to the ball.
Turns out, the wall applies the exact same amount of force back as the ball applied forward.
*EDIT: The comments below are excellent expansions. The wall doesn't seem to move, but there are vibrations throughout the wall (and so on) that account for that force. And yes, many other forces are acting on the wall.
EXPLAIN IT TO ME LIKE I'M 10: Maybe it's better to say "forces affect inertia - they can help or hurt it."