This question is based on the fundamental assumption of vector direction.
A vector is a physical quantity which has magnitude as well direction for its complete specification.
The magnitude of a physical quantity is simply a numerical number .Hence it can not be negative.
A negative vector is a vector which comes into existence when it is opposite to our assumed direction with respect to any other vector. For instance, the vector is taken positive if it is along + X axis and negative if it is along - X axis.
As per the first option it is given that a vector is negative if its magnitude is greater than 1. It is not correct as magnitude play no role in it.
The second option tells that the magnitude of the vector is less than 1. Magnitude can not be negative. So this is also wrong.
Third one tells that a vector is negative if its displacement is along north. It does not give any detail information about the negativity of a vector.
In a general sense we assume that vertically downward motion is negative and vertically upward is positive. In case of a falling object the motion is vertically downward. So the velocity of that object is negative .
So last option is partially correct as the vector can be negative depending on our choice of co-ordinate system.
the answer is B! it would continue to expand.....just took the test XD
Answer:
Mercury
Explanation:
The force of gravity is equal to the mass times the centripetal acceleration:
Fg = m v² / r
Also, the force of gravity is defined by Newton's law of universal gravitation, which states the Fg = mMG / r², where m and M are the masses of the objects, G is the universal constant of gravitation, and r is the distance between the objects.
mMG / r² = m v²/ r
MG / r = v²
This means the square of the orbital velocity is equal to the mass of the sun times the universal constant of gravity divided by the orbital radius. So whichever planet has the smallest orbital radius will have the highest orbital velocity. Of the four options, that would be Mercury.
The Sun shines by turning hydrogen into helium in its core, this process is called nuclear fusion. Fusion happens when lighter elements are forced together to become heavier elements. When this happens, a lot of energy is created.
