Answer:
Explanation:
Alright, lets get started.
Please refer the diagram I have attached.
Suppose Galileo should walk x meters on 15 degree inclined plane, and then he will get the 150 meter altitude and he could perform his experiments with the balls.
Now, using trigonometry, we know

Means

Plugging the value of sin 15

Hence,

So, Galileo must walk up 579.56 meters on inclined plane. : Answer