The rain drop of mass 1 g, starts with zero velocity from a height of 1 km. It hits the ground with a speed of 5 m/s. The work done by the unknown resistive force is _______ J. (take g = 10 m/s ^2 )

Step-by-step solution

Using the work-energy theorem, the total work done by all forces equals the change in kinetic energy: W_ g + W_ r = K mgh + W_ r = 1 2 mv^2 - 0 Substituting the given values ( m = 10⁻³ kg, g = 10 m/s ^2 , h = 1000 m, v = 5 m/s): (10⁻³)(10)(1000) + W_ r = 1 2 (10⁻³)(5)^2 10 + W_ r = 0.0125 W_ r = 0.0125 - 10 = -9.9875 J W_ r -9.98 J Answer: -9.98