A few days ago

physics please help?

1. Ur friend Maurice says that to apply the largest amount of torque to an object, you have to apply the greatest amount of force possible. Alicyn says that a small force is enough, but that the distance should be as large as possible. How would you settle this argument between your friends?

2. Bob is playing on a seesaw w/ his friend Courtney. Bob has a weight of 450N and he is sitting at the very end of his side of the 4m long seesaw. Where will Courtney, who weighs 600N, have to sit to balance the seesaw?

Top 2 Answers
A few days ago

Favorite Answer

Since torque is force times distance, both friends are right, depending of the situation. If the lever arm is of a fixed length, then Maurice is correct because force is the only thing that can be varied. If the force is fixed but the lever arm is variable, then Alicyn is correct.

Question 2 is one of balancing torque. Force (weight) on one side times its distance to the fulcrum must match the force (weight) on the other side times its distance to the fulcrum. Therefore, in the problem, we have 450N times 2 meters (half the seesaw) on one side. That equals 900 N-meters. On the other side we have 600 N times X meters for a total torque of 600N-meters. As an equation that would be:

(450 N) (2 meters) = (600 N) (X meters)

If we now divide both sides by 600 N, we would have:

1.5 meters = X where X is the distance sought.


A few days ago
To apply the maximum amount of torque you need both maximum distance and greatest amount of force since the formula for torque is:

Force x Distance to fulcrum x sin(angle force is applied to lever)

So neither is correct

2 using the formula above and assuming the angle the force is applied is at a right angle or 90 degrees leaves us with sin(90)=1 so that

450N times 2M = 600N times xM

solving for x leaves you with X = 900NM / 600N

X = 1.5 M