Every body presists in its state of being at rest of moving uniformly straight forward (constant vel...
Every body presists in its state of being at rest of moving uniformly straight forward (constant velocity), except insofar as it is compelled to change its state by force impressed，the law of inertia.
Unbalanced force, the two pair of balanced force can cancel each other.
Non-friction.
Friction come with atomic level, the actual water molecules and elastic structure and the ice cube here and the elastic structure on the ice. Beside, there are air particles.
Those situation without the gravity.
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Jurassicpark2014-09-13
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