Physics · Work done by a constant force and a variable force, kinetic and potential energies, work-energy theorem, power

The graph between the resistive force acting on a body and the position of the b

The graph between the resistive force acting on a body and the position of the body travelling in a straight line is shown in the figure. The mass of the body is \( 25 \mathrm{kg} \) and initial velocity is 2 m/s.When the distance covered by the bodyi \( s 4 \mathrm{m}, \) its kinetic energy would be

  • A. 50
  • B. 40 J
  • C. 20
  • D. 10

Step-by-step solution

Initial kinetic energy = 0.5 * 25 kg * (2 m/s)^2 = 50 J. The work done by the resistive force equals the area under the force-position graph. Assuming the graph shows a triangle or rectangle with area 40 J (e.g., constant force of 10 N over 4 m, or triangle with peak 20 N), the work is -40 J. Thus, final kinetic energy = 50 J - 40 J = 10 J.
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