Question Detail

PHY 101 PHY 101 Past Questions Objective Question

Question

Vectors A and B are given as A = 3i + 4j - 2k and B = 2i - 6j + 3k. Evaluate A × B.
Options
A 24i - 5j + 20k
B -13j - 26k
Correct Answer
C 24i + 5j - 4k
D 24i - 5j - 4k
Correct Answer

Option B is the correct answer.

Detailed Explanation

The cross product A × B is calculated using the determinant method: A × B = | i j k; 3 4 -2; 2 -6 3 | = i(4×3 - (-2)×(-6)) - j(3×3 - (-2)×2) + k(3×(-6) - 4×2) = i(12 - 12) - j(9 + 4) + k(-18 - 8) = 0i - 13j - 26k = -13j - 26k.

Hint

Use the determinant formula for cross product: A × B = |i j k; A_x A_y A_z; B_x B_y B_z|.

Question Info