Answer:
man will move in opposite direction with speed

Explanation:
As we know that man is lying on the friction-less surface
so here net force along the surface is zero
so if we take man + stone as a system then net change in momentum of this system will become zero
so here we have


here we have



Answer:
2.96 cm
Explanation:
By Hook's law
Force(F) = Spring constant(k) × Extension(d)
F = k × d
Force is the weight of the object, F = W = mg
So we get, mg = kd ⇒ m ∝ d
2.5 ∝ 1.68 --------------(1)
4.4 ∝ d' --------------(2)
From (1) & (2), 4.4/2.5 = d'/1.68
d' = 2.96 cm ⇒ the required extension.
Organisms, organs, tissues, cell ....
a more specific answer would be:
organism, organ system, organ, tissue, cell, atom
Momentum is a property of moving objects but not stationary objects. You can see this in the formula because momentum equals mass times velocity squared (p=m*v^2). You would not have momentum if you didn't have velocity. Stationary objects have potential energy, and things with potential energy do not have velocity. This is why momentum is a property of moving objects but not of stationary objects.
B. The answer is most likely B