Question

Good morning, i really just had a simple question. I was solving this problem:

"Two children weighing 48 pounds and 72 pounds are going to
play on a seesaw that is 10 feet long."
And it basically was asking me for the equilibrium. I set the problem up like this:
M1=72, M2=48, X1=0, X2=10
X=(72(0)+48(10))/72+48= 480/120
Answer:4 ft
but when i checked the answer, it was 6ft, due to M1= 48, so my question is.....why does the smaller child(48lbs) become M1 as to him being M2

Answer 1

Answer: Your answer is completely correct. It is just that when answering the question, you should assume that the 48 lb child is on the left, and the 72 lb child is on the right. Usually, I always assume that the first mentioned item is the left most one.

Explanation:

This is how I will set up the problem: M1 = 48 lbs, M2 = 72 lbs, L = 10 ft

Since (M1 * 0 + M2 * 10)/(M1+M2) = equilibrium, we can use this equation to find the solution:

0 + 720 / (48+72) = 6 feet