February 21, 2017

Homework Help: Physics, Someone please help me!

Posted by Tia on Wednesday, November 7, 2012 at 12:47pm.

A person bending forward to lift a load with his back, as shown in the figure, rather than with his knees can be injured by large forces exerted on the muscles and vertebrae. The spine pivots mainly at the fifth lumbar vertebra, with the principal supporting force provided by the erector spinalis muscle in the back. To see the magnitude of the forces involved, and to understand why back problems are common among humans, consider the model shown in the figure of a person bending forward to lift a 160 N object. The spine and upper body are represented as a uniform horizontal rod of weight 420 N, pivoted at the base of the spine. The erector spinalis muscle, attached at a point two-thirds of the way up the spine, maintains the position of the back. The angle between the spine and this muscle is 12.0°. Find the tension in the back muscle (T).

Answer This Question

First Name:
School Subject:

Related Questions

More Related Questions