Answer: Lol, it just says “Invisible”, but ngl it is pretty cool
Answer:

Step-by-step explanation:
From the question we are told that:
Weight of Roger 
Distance of Roger from fulcrum 
Weight of Ellen 
Generally the equation for distance-weight relationship is mathematically given by


Therefore




Therefore the distance from the fulcrum she must sit to balance the seesaw is given as

Hello Hope this can help you.
If you need any more help feel free to ask me.
Good luck mate :P
9.5 inches is your answer because you would divide 38 by 4
1. Is two minutes because you can see that the rate stays the same until that point.
2. 10 cm because that’s what it shows on the side
3. 30 cm as that’s where the water stops rising
4. 3 minutes
5, 25 cm because that’s where the water stops
6. 2 minutes
Hope this helps!