Jump to content

Walking the plank

Lizwi
in Classical Physics

Featured Replies

I was looking at this example attached, if I change the origin, I get two times the answer from the book.

My attempt is hand written on the attachment.

Why is my answer different.

compressed_1658685834IMG_20190421_105343.jpg

compressed_794448646IMG_20190421_110103.jpg

Spoiler

Where did you get the "3.75"?  Is that the distance from the right hand end of the plank to the left support?  The left support is irrelevant.  If the plank starts to pivot because of weight on the right end, it will pivot on the right support.  I think that "3.75" should be 3- .75= 2.75.

 

  • Author

3.75 is the distance from S1 to the person, since my origin is at S1. 

 

The distance between the two saw horses is 1.5m, and the distance from the centre of the blank is 3m so if you work out you can see that the distance from sawhorse 1 is 3.75m.

Archived

This topic is now archived and is closed to further replies.

Go to topic listing

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.

Configure browser push notifications
Chrome (Android)
  1. Tap the lock icon next to the address bar.
  2. Tap Permissions → Notifications.
  3. Adjust your preference.
Chrome (Desktop)
  1. Click the padlock icon in the address bar.
  2. Select Site settings.
  3. Find Notifications and adjust your preference.