Question Detail

PHY 101 PHY 101 Past Questions Objective Question
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Question

Find the magnitude of the vector 2A + 3B, given that A = 6i + 3j - k and B = 4i - 5j + 8k.
Options
A 21j - 26k
B 24i - 9j + 22k
Correct Answer
C -24i + 9j - 22k
D 12i + 6j - 2k
Correct Answer

Option B is the correct answer.

Detailed Explanation

2A = 12i + 6j - 2k. 3B = 12i - 15j + 24k. Sum = (12+12)i + (6-15)j + (-2+24)k = 24i - 9j + 22k. Magnitude = √(24² + (-9)² + 22²) = √(576 + 81 + 484) = √1141 ≈ 33.78. The options show the vector, not magnitude. Option B is the correct vector.

Hint

Add component-wise after scalar multiplication.

Question Info

Course: PHY 101
Topic: PHY 101 Past Questions
Type: Objective
Difficulty: Not specified
Question 899 of 1250
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