A particle moves with a velocity 6 i - 4 j + 3 k ,m/s under the i… - Vidyadip

MCQ

A particle moves with a velocity $6\hat i - 4\hat j + 3\hat k\,m/s$ under the influence of a constant force $\overrightarrow F = 20\hat i + 15\hat j - 5\hat k\,N.\,$ The instantaneous power applied to the particle is......... $J/s$

A
$35$
✓
$45 $
C
$25$
D
$195$

✓

Answer

Correct option: B.

$45 $

b
(b) $P = \vec F.\vec v = 20 \times 6 + 15 \times ( - 4) + ( - 5) \times 3$

$ = 120 - 60 - 15 = 120 - 75 = 45\,J/s$

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