Question

2.A force is represented by F =(21 +3j +6k) N. The magnitude is
a) √29
b) √41
c) 5
d) 7​

Answer 1

Answer:

21 j may be the answer I think

Answer 2

Answer:

The magnitude of the force is 7N.i.e.option(d).

Explanation:

A force is a vector having both magnitude and direction. And the resultant of a vector is defined as the square root of the vector.

For example, if force is represented as,

$\vec{F}=x\hat{i}+y\hat{j}+z\hat{k}$               (1)

And the magnitude of this force vector is given as,

$F=\sqrt{x^2+y^2+z^2}$             (2)

The force vector given in the question is,

$\vec{F}=2\hat{i}+3\hat{j}+6\hat{k}$       (3)

By substituting equation (3) in equation (2) we get;

$F=\sqrt{2^2+3^2+6^2}=\sqrt{49}=7N$

Hence, the magnitude of the force is 7N.i.e.option(d).