Two boys and their father are balance on a seesaw. The father, 70kg, sits on one end 0.65m from the center of the seesaw while the two boys sit together on the other end. If each boy weighs 30kg, where should they sit?
Mg•L=2mg•x
70•0.65 = 2•30x
x=70•0.65/60=0.75 m
0.8M
To find out where the two boys should sit on the seesaw, we need to apply the principle of moments, also known as the law of levers. The principle of moments states that the clockwise (negative) moments are equal to the counterclockwise (positive) moments, causing the seesaw to be balanced.
First, let's calculate the moment created by the father's weight on one end of the seesaw. The moment is the product of the force (weight) and the distance from the center. In this case, the father's weight is 70 kg, and the distance from the center is 0.65 m:
Moment of the father = 70 kg × 0.65 m = 45.5 kg·m (clockwise moment)
Since we have two boys sitting together on the other end of the seesaw, their total weight is 30 kg + 30 kg = 60 kg.
Now, let's assume that the two boys sit at a distance 'd' from the center. We need to find the value of 'd' that creates an equal and opposite moment to balance the seesaw.
Moment of the two boys = 60 kg × d
To balance the seesaw, the clockwise moment (45.5 kg·m) should be equal to the counterclockwise moment (60 kg × d). So, we can set up an equation:
45.5 kg·m = 60 kg × d
Now, let's solve for 'd':
d = (45.5 kg·m) / (60 kg)
d ≈ 0.758 m
Therefore, the two boys should sit approximately 0.758 meters from the center of the seesaw to balance it with the father sitting on the other end.