Question

Which of the following is not a vector quantity?
A) Weight
B) Nuclear spin
C) momentum
D) potential energy

Answer 1

Hint : In this solution, we will check the different quantities whether they are vector quantities or not. A vector quantity has both direction and magnitude associated with it.

Complete step by step answer
In option (A), weight is actually a vector quantity since weight is not equal to the mass of an object. It is the product of the mass of an object and the gravitational acceleration it experiences. Since the gravitational acceleration of the object is a vector quantity, the product of a scalar and a vector quantity will be a vector quantity so option (A) is not correct.
In option (B), nuclear spin is also a vector quantity since it is equivalent to the total angular momentum of the atom. The nucleus of an atom behaves like tiny rotating magnets that are associated with the spin of the nucleus. The direction of the spin will be along the axis of rotation of the spin so option (B) is also not correct.
In option (C), the momentum of an object is equal to the product of mass and velocity of an object and since velocity is a vector quantity, so will momentum be. Hence option (C) is also not the correct choice.
In option (D), the potential energy of a body is scalar in nature as it does not have any direction associated with it. It only has a magnitude associated with its capacity to do work also known as potential energy.
Hence option (D) is correct.

Note
We must not confuse weight with mass since mass is a scalar quantity however weight is a vector quantity. The potential energy of a body can be due to various forces like electrical, gravitational, mechanical, etc however regardless of the force at play, the potential energy will always be scalar.