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A force of 6 hat i+ 7 hat j newton make...

A force of ` 6 hat i+ 7 hat j` newton makes a body move on a rough loane with a velocity of (4 hat j = 3 hat k) ms^(-1)` . Calculate the power in watt.

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Here, ` vec F = 6 hat I + 7 hat j , vec v= 34 hat j + 3 hat k`
Power, ` P= Fvec F. vec v= ( 6 hat I + 7 hat j).(4 hat + 3 hat k)`
` = 24 ( hat i.hat j) + 18 ( hat . Hat k)+ 28 ( hat j. hhat j) + 21 (hat j. hat k)` ltbRgt `= 24 (0) + 18 (0) + 28 (1) + 21 (0)`
` =28 W`.
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