Concepts Of Physics MCQ Edition [Volume 1]PhysicsPhysics and Mathematics
Let a be a vector of magnitude 4.5 unit pointing due north. Evaluate the vector 3 a .
Options
- A13.5 unit due north
- B1.5 unit due north
- C13.5 unit due south
- D7.5 unit due north
Correct answer
A. 13.5 unit due north
Step-by-step solution
Given that the magnitude of vector a is | a | = 4.5 units and its direction is due north. When a vector is multiplied by a positive scalar, its magnitude is multiplied by the scalar and its direction remains unchanged. The magnitude of the new vector 3 a is 3 | a | = 3 4.5 = 13.5 units. Since 3 is a positive number, the direction of 3 a is the same as a , which is due north. Thus, 3 a is 13.5 units due north.