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A particle acted by constant forces 4 ...

A particle acted by constant forces `4 hat i+ hat j-3 hat k and 3 hat i+ hat 9j- hat k` is displaced from point ` hat i+2 hat j+3 hat k` to point `5 hat i+4 hat j+ hat kdot` find the total work done by the forces in SI units.

Text Solution

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`Here vecF=vecF_(1)+vecF_(2)=(4hati+hatj-3hatk)+(3hati+hatj-hatk)=7hati+2hatj-4hatk`
`and vecd=vecd_(2)-vecd_(1)(5hati+4hatj+hatk)-(hati+2hatj+3hatk)=4hati+2hatj-2hatk`
Work done = `vecF.vecd`
`=(7hati+2hatj-4hatk).(4hati+2hatj-2hatk)`
= (7) (4) + (2) (2) + (-4) (-2)
= 28 + 4 +8 = 40 units.
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