It is well known that a raindrop falls under the influence of the downward gravitational force and the opposing resistive force. The latter is known to be proportional to the speed of the drop but is otherwise undetermined. Consider a drop of mass 1.00g falling from a height 1.00km. It hits the ground with a speed of 50.0 ms^(-1). What is the work done by the gravitational force?

It is well known that a raindrop falls under the influence of the down

1.	It is well known that a raindrop falls under the influence of the downward gravitational force and the opposing resistive force. The latter is known to be proportional to the speed of the drop but is otherwise undetermined. Consider a drop of mass 1.00g falling from a height 1.00km. It hits the ground with a speed of 50.0 ms^(-1). What is the work done by the gravitational force?
Answer» Solution :The change in kinetic ENERGY of the drop is `triangleK= (1)/(2)mv^(2)-0` `=(1)/(2)xx10^(-3)xx50xx50 = 1.25 J` where we have assumed that the drop is initially at rest. Assuming that G is a constant with a value `10 m"/"s^(2)`, the work done by the gravitational force is, `W_(g)= mgh` `=10^(-3)xx10xx10^(3)= 10.0 J`.