A particle moves from position r= 3i+2j-6k to r= 14i+13j+9k under the action of a Force F= 8i+2j+6k. Find the work done by the force:
Correct answer: E. 200 units
- A. 50 units
- B. 75 units
- C. 125 units
- D. 155 units
- E. 200 units
Explanation
Work done = force×displacement Given data:F=8i+2j+6k N Now displacement, d=(14i+13j+9k) - (3i+2j-6k)d=(14-3)i+(13-2)j+(9-[-6])k d=11i+11j+15k Now, W=F×d W= (8i+2j+6k) × (11i+11j+15k) W=(11×8)+(2×11)+(6×15)W=88+22+90 W=200J
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