MHT CET202618 April 2026Evening ShiftPhysicsMathematics in PhysicsActual
If a unit vector is represented by U = 0.9 , i - 0.2 , j + m k , then the value of m is
Options
- A0.85
- B0.15
- C1
- D0.77
Correct answer
B. 0.15
Step-by-step solution
Given U = 0.9 i - 0.2 j + m k is a unit vector. The magnitude of a unit vector is 1 . | U | = (0.9)^2 + (-0.2)^2 + m^2 = 1 Squaring both sides: 0.81 + 0.04 + m^2 = 1 0.85 + m^2 = 1 m^2 = 1 - 0.85 m^2 = 0.15 m = 0.15 Answer: 0.15