Question

Weight is a vector quantity.

Answer 1

Answer:On earth, weight of a body is defined as the force by which the body is attracted by the earth towards its center. Weight can thus be considered the same as the gravitational force exerted by the earth on that body. Hence, weight can be deemed a vector since it is a force, irrespective of the planet you consider.

W⃗ =mg⃗ =GMmr2r^

W→=mg→=GMmr2r^

As mentioned in the comments, since gg has the same direction (directed towards the center of the concerned planet) always, it might be(?) considered a scalar. Thats what your prof is doing. But strictly speaking, weight is a vector.

Hope this helps you.

Explanation: