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Newton's third law states that forces aren't equal in magnitude?

I'm doing the Edexcel physics sample paper 1, however I'm really confused about question 6, as when I check the mark scheme it seems that it's stating that in newton's third law the forces aren't of equal magnitude, but I thought they would be. Can someone explain?

Link to paper: https://b3ae635e4bdf744d473ecb30b9357f7a90b076ba.googledrive.com/host/0B1ZiqBksUHNYZWE4SzdPaWZ1d28/Specimen%20QP%20-%20Paper%201%20Edexcel%20Physics%20AS-Level.pdf

Link to mark scheme: https://b3ae635e4bdf744d473ecb30b9357f7a90b076ba.googledrive.com/host/0B1ZiqBksUHNYZWE4SzdPaWZ1d28/Specimen%20MS%20-%20Paper%201%20Edexcel%20Physics%20AS-Level.pdf
Reply 1
I'd say it's an error in the mark scheme, I do OCR A but we are taught that the third law is that "If object A were to exert a force on object B, then object B would exert an equal but opposite force on object A", with the conditions being that the forces are of the same type (contact, gravitational), and act on two different bodies. So a pair would be the force of earths gravity on a ball, and the force of the balls gravity on earth.
I'd say the answer is B.
Original post by SpaghettiGuy1337
I'm doing the Edexcel physics sample paper 1, however I'm really confused about question 6, as when I check the mark scheme it seems that it's stating that in newton's third law the forces aren't of equal magnitude, but I thought they would be. Can someone explain?

Link to paper: https://b3ae635e4bdf744d473ecb30b9357f7a90b076ba.googledrive.com/host/0B1ZiqBksUHNYZWE4SzdPaWZ1d28/Specimen%20QP%20-%20Paper%201%20Edexcel%20Physics%20AS-Level.pdf

Link to mark scheme: https://b3ae635e4bdf744d473ecb30b9357f7a90b076ba.googledrive.com/host/0B1ZiqBksUHNYZWE4SzdPaWZ1d28/Specimen%20MS%20-%20Paper%201%20Edexcel%20Physics%20AS-Level.pdf


The mark scheme is wrong. The answer is B.
Alright, cheers guys. Sample papers aren't perfect it seems :wink:

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