Between the bumps and dips of two surfaces. SO the answer is 2 surfaces. Hope this helps! :)
Answer:
Mechanical advantage = 3
Explanation:
You exert a 100-N force on a pulley system to lift 300-N.
The mechanical advantage of the system is given by the ratio of output force to the input force.
Here, output force = 300 N and input force = 100 N
Mechanical advantage,

Mechanical advantage is 3 it means that there are 3 sections of rope support. Hence, this is the required solution.
Yo sup??
since the collision is elastic therefore we can say that the two balls will then move in opposite direction.
If ball 1 was moving from east to west then after collision it will move from west to east
and if ball 2 was moving from west to east then it will start moving from east to west.
Hope this helps.