A young child is pulling a sled in the snow. if the force the child exerts on the sled is equal to the force the sled exerts on child but opposite direction, how is it possible that the child can pull the sled forward

Question

anonymous · Answer

Because the friction between the sled and the snow is very low, and the child is pulling with enough force to overcome that friction.  The sled pulls on the child's arm with the same force that the child pull's on the sled.  That is manifested in the pulling sensation--i.e. the tension in the child's arm.

theeric · Answer

And you have to think, the child won't slide as easily. The child's boots probably hold onto the snow much better!

If you have questions, feel free to ask! The more you ask, the better you'll understand. The more you try to find questions, the more you'll be thinking, and the more you'll understand.

anonymous · Answer

There are two force reaction pairs:  there's the child pulling on the sled and the sled pulling back (creating the tension in the child's arm); and there are the child's feet pushing on the snow and the snow pushing the child's feet, thus propelling the child forward.

theeric · Answer

And if it doesn't propel the child forward, it can still be the force that keeps the child stationary while the child moves the sled. If the child is on ice, with slick shoes, the child will move when the child tugs on the sled. But, in snow, the snow will put a force on the child so that the child does not get pulled back.