How Is Torque Calculated on a Diving Board?

[PeachBanana]

Homework Statement

Calculate the torque (magnitude and direction) about the front support post (B) of a diving board , exerted by a 60 kg person 3.0 m from that post. See picture.

Homework Equations

τ = Fr

The Attempt at a Solution

τ clockwise = τ counterclockwise

(60 kg)(9.8 m/s^2)(4.0 m) = τ counterclockwise

I used "A" as the origin. Did I approach this incorrectly?

 

[cepheid]

They asked you to compute the torque around point B.

Also, you just need to compute the torque due to the person

 

[PeachBanana]

Oh I see. By using 4.0 m I considered the torque around point A.

(60 kg)(9.8 m/s^2)(3.0 m) ≈ 1800 N * m

 

[cepheid]

Seems okay

 

[asteriatic]

I can confirm that your approach to solving this problem is correct. You have correctly applied the equation for torque, which states that the clockwise torque must be equal to the counterclockwise torque in order for the object to be in rotational equilibrium. Using the given information, you have correctly calculated the clockwise torque exerted by the person on the diving board and set it equal to the counterclockwise torque exerted by the diving board on the person. Your choice of "A" as the origin is also appropriate, as it allows you to calculate the distance from the front support post (B) to the point of application of the force (the person) as 4.0 m. Great job!