Question

A man starts from rest at a point A(1;2;-3)

Answer 1

Answer:

◆ Answer -

(d) |AB| = 8.5 m

● Explaination -

Let i, j & k be unit vectors along X-axis, Y-axis & Z-axis.

A = i + 2j - 3k

B = 3i + 4j + 5k

Displacement of the man is calculated by -

AB = B - A

AB = (3i + 4j + 5k) - ( i + 2j - 3k)

AB = 2i + 2j + 8k

Magnitude of displacement is calculated by -

|AB| = √(2² + 2² + 8²)

|AB| = √(4 + 4 + 64)

|AB| = √(72)

|AB| = 2√18

|AB| = 8.48 m

From the options, 8.5 m is the most appropriate.