Torque Problem (Door)

Question

Question: Two children push on opposite sides of a door during play. Both push horizontally and perpendicular to the door. One child pushes with a force of 17.5 N at a distance of 0.600 m from the hinges, and the second child pushes at a distance of .450 m. What force must the second child exert to keep the door from moving? Assume friction is negligible.

Additional questions related to the problem: Does this problem concern "center of gravity"? What is the difference between center of gravity and point of rotation? How would a force diagram of this situation look like?

Answer 1

We need both torques to be the same so (17.5 N)(0.6 m) =(F)((.45 m)

So the second child should push with 23.3 N