Question

The resultant of two vectors of magnitudes 3 units and 5 units is perpendicular to 3 units.the angle between the vectors is

Answer 1

Answer:

$127^{\circ}$

Explanation:

1) Given two vectors of magnitude 3 and 5 units such that its resultant is perpendicular to that of 3 units.

Let both vectors are such that angle between them is $\theta$

2) Making components of 5 units vector such that its horizontal component is equal to that of 3 units as shown in figure.

$-5cos(\theta)=3\\ \\=>cos(\theta)=\frac{-3}{5}\\ \\ =>\theta \approx 127^{\circ}$

Hence, to make vectors of 3units and 5units such that their resultant is perpendicular to 3units vector, angle between them can be 127 degree.

See figure attached.