An object is displaced from point A (2,3,4) m to point B (1,2,3) m under a constant force F=( 2i+3j+4k). Find the work done by this force in this process.
Correct answer: C. -9J
- A. 9J
- B. 0J
- C. -9J
- D. 20J
Explanation
Correct Option:CAs the force is given as,F=2i+3j+4kThe displacement d with initial point (x1,y1z1) and terminal point (x2,y2,z2)So,d=(x2-x1, y2 -y1, z2-z1)d=(1-2 ,2-, 3-4) d=(-1,-1,+1)d=(-i,-j,-k)As from the formula work doneW =F.SW = (2i+3j+4k),(-i-j-k)W=-2-3-4 W=-9 jolueThus this is the correct option
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About Work
Work is done when a force produces displacement, with its value determined by the component of force along the displacement. The topic covers positive, negative and zero work, work by variable forces from force-displacement graphs, and the connection between net work and change in kinetic energy.
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