A good question

A man is standing on a frictionless surface and there is no air resistance. If he wants to move, which of Newton's laws would he be using?
1) cant say
2) 1st law
3) 2nd law
4) 3rd law

4 Answers

Amartya Kumar Mistry ·

The answer may be third law bcoz a component of his normal reaction on the floor would help him to move forward


3rd law. The man will apply a force on the ground (in the horizontal direction). The ground will apply a reaction force on the man. The vertical component of the force applied by the ground balances the weight of the man,while the horizontal component of the force applied by the ground helps the man to move forward.

Himanshu Giria ·

1st law

Sahil Jain ·

This is ambigous question. The answer could hav also been 1st law. As the conservation of momentum (I mean Newtonian not quantum) can be completely derived from 1st law. And the perfect answer would be conservation of momentum .
1.If he wants to move by walking---sorry there's no friction on surface.
2.If he wants to move through expelling air----Sorry,no resistance by the air.
Then there must be an external agency,an external push or effort to make him move.

  • Swastik Haldar he can just pull something out of his pocket and throw it the opposite direction. As there is no external force on the system, the centre of mass will not change. so when he thows a mass in a direction, he should move in the opposite direction in order to keep the COM stationary.

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