Two children seat themselves on a seesaw.The one on the left has a weight of 400 N while the one on the right weighs 300 N.The fulcrum is at the midpoint of the seesaw.If the child on the left is not at the end but is 1.50 m from the fulcrum and the seesaw is balanced,what is the torque provided by the weight of the child on the right?
A)600 N*m
B)450 N*m
C)-600 N*m
D)-450 N*m

Question

Quizplus · Accepted Answer

In order for the seesaw to balance, the torque provided by the child on the left must be equal and opposite to the torque provided by the child on the right. We can calculate the torque provided by the child on the left as follows:

Torque (left) = Force (left) x Distance (left)
Torque (left) = 400 N x 1.50 m
Torque (left) = 600 Nm

Since the seesaw is balanced, the torque provided by the child on the right must be equal and opposite:

Torque (right) = -600 Nm

We can also calculate the force provided by the child on the right using the formula for torque:

Torque = Force x Distance
-600 Nm = Force (right) x 0.75 m
Force (right) = -800 N

The negative sign indicates that the force provided by the child on the right acts in the opposite direction to the force provided by the child on the left. Therefore, the torque provided by the weight of the child on the right is -600 Nm, which corresponds to choice C.

Two Children Seat Themselves on a Seesaw