A particle moves from position r1=3i^+2j^−6k^ to position r2=14i^+13j^+9k^ under the action of force 4i^+j^+3k^ N. The work done will be:
A
100 J
B
50 J
C
200 J
D
75 J
Step-by-Step Solution
Given,
Initial position vector, r1=3i^+2j^−6k^
Final position vector, r2=14i^+13j^+9k^
Force acting on the particle, F=4i^+j^+3k^ N
The displacement vector d is given by:
d=r2−r1d=(14i^+13j^+9k^)−(3i^+2j^−6k^)d=(14−3)i^+(13−2)j^+(9+6)k^=11i^+11j^+15k^
The work done W by a constant force is the dot product of the force vector and the displacement vector :
W=F⋅dW=(4i^+j^+3k^)⋅(11i^+11j^+15k^)W=(4×11)+(1×11)+(3×15)W=44+11+45=100 J
Thus, the work done is 100 J.
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