Gravitational potential energy concept question

[Mdhiggenz]

Homework Statement

A piece of fruit falls straight down. As it falls,

A. the gravitational force does positive work on it and the
gravitational potential energy increases.
B. the gravitational force does positive work on it and the
gravitational potential energy decreases.
C. the gravitational force does negative work on it and the
gravitational potential energy increases.
D. the gravitational force does negative work on it and the
gravitational potential energy decreases.

The correct answer is B

Homework Equations

The Attempt at a Solution

I want to make sure my reasoning is correct. The answer would be B because when the piece of fruit falls the only force acting upon it is gravity. So relating this to the gravitational potential energy equation Ugrav= Mgy; as the fruit falls its displacement is decreasing due to it getting closer and closer to zero thus making the over all gravitational potential energy decrease.

Thank you

 

[2sin54]

That's right. And the work done by gravitational force is positive, because the fruit is moved in the same direction as the force is pointed to.