Bob (200kg) and Sally (40kg) want to make a see saw that will balance when they are both on 8it. If the board they have is 5m long, where should the fulcrum be placed?
x is distance from fulcrum for Bob.
Then 5-x = distance for Sally.
200*x = 40*(5-x)
Solve for x and 5-x.
thank you very much! :)
To find the placement of the fulcrum, we need to take into account the weights of Bob and Sally, as well as their distances from the fulcrum.
Let's denote the distance from the fulcrum to Bob as x and the distance from the fulcrum to Sally as (5 - x) since the total length of the board is 5 meters.
The condition for balancing a seesaw is that the total torque on one side equals the total torque on the other side. Torque is the product of weight and distance, given by the formula: Torque = weight * distance.
So, for the seesaw to balance, the torque on one side (Bob's side) should be equal to the torque on the other side (Sally's side).
The torque on Bob's side is 200 kg * x m, and the torque on Sally's side is 40 kg * (5 - x) m.
Setting these two torques equal to each other, we get:
200x = 40(5 - x)
Now, let's solve this equation for x:
200x = 200 - 40x
240x = 200
x = 200 / 240
x ≈ 0.83
Therefore, the fulcrum should be placed approximately 0.83 meters from Bob's side. To find the distance from Sally's side, we subtract this value from the total length of the board, so (5 - x) ≈ 4.17 meters.
So, the fulcrum should be placed at approximately 0.83 meters from Bob's side and 4.17 meters from Sally's side to balance the seesaw with Bob weighing 200kg and Sally weighing 40kg.