A raindrop weighing 40 mg fell from a height of 1.5 km. determine the work of gravity.

With a straight drop falling and a constant value of the force, the work of the force of gravity is:
A = F * S * cos (F, S), where F is the force of gravity (F = m * g (m is the mass of the drop (m = 40 mg = 40 * 10 ^ -6 kg), g is the acceleration of gravity ( we take g = 9.8 m / s ^ 2)), S is the movement of the drop (S = 1.5 km = 1500 m), cos (F, S) = cos 0 = 1 (since the direction of gravity and displacement coincide ).
A = F * S * cos (F, S) = (40 * 10 ^ -6) * 9.8 * 1500 = 0.588 J = 588 * 10 ^ -3 J = 588 mJ.
Answer: The work of gravity is 588 mJ.