Help please?
1 Answer
Mar 11, 2018
D
Explanation:
We know that work is total force times distance traveled.
There's a few we can immediately eliminate:
We know that the ball has weight, so it isn't a.
The ball is traveling, so we know it travels a distance, i.e. it's not e.
We can easily realize that b and c are pretty much the same statement: kinetic energy is changing into potential energy to change magnitude. But we can have a system without work that does this, such as throwing a ball in the air. Therefore, b and c are not the answer.
D is the answer because we can express the work as
and the inner product is 0 since the forces are all vertical.
(I'm a physics major and this is a confusingly worded question)