How Does Newton's Third Law Apply Here?

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SUMMARY

The discussion centers on applying Newton's Third Law to a physics problem involving a 40 kg girl and a 50 kg boy on a frozen lake, where the girl exerts a horizontal force of 5.0 N on the boy. The key takeaway is that both the girl and the boy experience equal and opposite forces due to the rope tension, which affects their respective accelerations. The girl’s acceleration can be calculated using the formula F=ma, taking into account the total mass of both individuals when analyzing the system.

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Newton's law "trick?" question

Homework Statement


A 40 kg girl and a 50 kg boy are on the surface of a frozen lake, 10 m apart. Using a rope, the girl exerts a horizontal 5.0 N force on the boy, pulling him toward her. Calculate the magnitude of the girl's acceleration.

Homework Equations



F=ma

The Attempt at a Solution


i don't really know where the distance from the problem comes in and its not as simple as it looks... apparently.
I thought about how if the girl pulled the rope with 5N then the only mass that's moving is the boy, but that wasn't right. Adding the weights together didn't work either.
THe hint i got was "Newton's 3rd law"
how will that apply to this problem? i understand the concept of the 3rd law.

Thanks!
 
Last edited:
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iamtrojan3 said:
i understand the concept of the 3rd law.

Then what would be the force on the girl?
 


Yea... misread question >.<
i hate when that happens
thanks.
 

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