2.5 kg because you cant change the weight of the rock
Answer:
100N
Explanation:
Newton's third law of motion
For every action, there is an equal and opposite reaction.
Therefore 100N of force is exerted by the crate on student as a reaction to his action
Answer:
"Magnitude of a vector can be zero only if all components of a vector are zero."
Explanation:
"The magnitude of a vector can be smaller than length of one of its components."
Wrong, the magnitude of a vector is at least equal to the length of a component. This is because of the Pythagoras theorem. It can never be smaller.
"Magnitude of a vector is positive if it is directed in +x and negative if is is directed in -X direction."
False. Magnitude of a vector is always positive.
"Magnitude of a vector can be zero if only one of components is zero."
Wrong. For the magnitude of a vector to be zero, all components must be zero.
"If vector A has bigger component along x direction than vector B, it immediately means, the vector A has bigger magnitude than vector B."
Wrong. The magnitude of a vector depends on all components, not only the X component.
"Magnitude of a vector can be zero only if all components of a vector are zero."
True.
By the work energy theorem, the total work done on the stone is given by its change in kinetic energy,

We have


Then the total work is
