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JEE · NEET Previous Year Question

$If F = (60 i + 15 j - 3 k) N and v = (2 i - 4 j + 5 k) m / s, then instantaneous power is$

Topic: NEET PYQ

Answer: B. Full step-by-step solution below.

A $195 watt$
B $45 watt$
C $75 watt$
D $100 watt.$

Correct answer: B

Solution

(b): P = F \cdot v = (60 i + 15 j - 3 k) \cdot (2 i - 4 j + 5 k) = 120 - 60 - 15 = 45 watts.

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