A particle moves with a velocity (5i -3j + 6k) ms-1 undre the influence of a constant force F=(10 i +10 j +20 K)N . The instantaneous power applied to the particle is

Question

A particle moves with a velocity (5i -3j + 6k) ms-1 undre the influence of a constant force F=(10 i +10 j +20 K)N . The instantaneous power applied to the particle is (A) 200 Js-1 (B) 40 Js-1 (C) 140 Js-1 (D) 170 Js-1

Tardigrade Admin · Accepted Answer

Velocity v = (5i - 3j + 6k) ms-1 and force F = (10i + 10j + 20k ) N hence Power P = F. v = (10i + 10j + 20k) (5i -3j + 6k) = 50-30+120 = 140 W = 140 Js-1

Q. A particle moves with a velocity $(5 i - 3 j + 6 k) m s^{- 1}$ undre the influence of a constant force $F = (10 i + 10 j + 20 K) N .$ The instantaneous power applied to the particle is

$200 J s^{- 1}$

$40 J s^{- 1}$

$140 J s^{- 1}$

$170 J s^{- 1}$

Velocity v = (5i - 3j + 6k) $m s^{- 1}$
and force F = (10i + 10j + 20k ) N
hence Power P = F. v
$= (10 i + 10 j + 20 k) (5 i - 3 j + 6 k)$
= 50-30+120
= 140 W = 140 $J s^{- 1}$

Q. A particle moves with a velocity (5i−3j+6k)ms−1 undre the influence of a constant force F=(10i+10j+20K)N. The instantaneous power applied to the particle is

200Js−1

40Js−1

140Js−1

170Js−1