Question 4 of 18intermediate🔍 AnalyzeShort Answer2 marks

State with reasons, whether the following algebraic operations with scalar and vector physical quantities are meaningful:

(a)

adding any two scalars,

Answer

Meaningful. Scalars follow the rules of ordinary algebra and can be added.

(b)

adding a scalar to a vector of the same dimensions,

Answer

Not meaningful. A scalar has magnitude only, while a vector has both magnitude and direction; they cannot be added.

(c)

multiplying any vector by any scalar,

Answer

Meaningful. A vector multiplied by a scalar results in a vector.

(d)

multiplying any two scalars,

Answer

Meaningful. Scalars follow ordinary algebra and can be multiplied.

(e)

adding any two vectors,

Answer

Meaningful. Two vectors may be added using graphical methods.

(f)

adding a component of a vector to the same vector.

Answer

Not meaningful. A component of a vector is a scalar, which cannot be added to a vector.

Explanation

The answer is derived from the textbook definitions of scalars and vectors. Scalars are quantities with magnitude only and follow ordinary algebra, allowing operations like addition and multiplication between them. Vectors have magnitude and direction and follow special vector algebra rules; they can be added to other vectors or multiplied by scalars, but cannot be added to scalars. For part (f), the text defines components like AxA_x as Acos⁡θA \cos \theta, which are scalars, making addition to a vector meaningless.