Two children are balancing on a teeter-totter. One child has a mass of 30.0 kg and is sitting 1.3 meters from the pivot. The second child is sitting 0.8 meters from the pivot. What is the mass of the second child
To find the mass of the second child, we can use the concept of torque. Torque is the rotational equivalent of force and is calculated by multiplying the force applied to an object by the distance from the pivot point.
In this case, the torque due to the first child can be calculated as:
Torque1 = mass1 * distance1
Substituting the given values:
Torque1 = 30.0 kg * 1.3 meters
Torque1 = 39.0 Nm
Now, since the teeter-totter is balanced, the torques on both sides of the pivot point must be equal. Therefore, the torque due to the second child can be written as:
Torque2 = mass2 * distance2
Since the torques are equal, we have the equation:
Torque1 = Torque2
Substituting the known values, we get:
39.0 Nm = mass2 * 0.8 meters
Now, we can solve for the mass of the second child:
mass2 = 39.0 Nm / 0.8 meters
mass2 = 48.75 kg
Therefore, the mass of the second child is approximately 48.75 kg.
The total moment about the pivot will be zero when there is balance. Write that as an equation and solve for the unknown mass.
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