2. A person is doing a sit-up (lie on their back and raise their torso up while keeping their lower body stationary). Use the hips as a pivot point and imagine their upper body stays rigid and straight throughout the motion. The person has a mass of m = 31 kg and lifts themselves with a constant speed. The center of mass of the torso is r, = 31 cm from the hip and the abdominal muscles apply a force r2 12 cm from the hip. Approximate the direction of the force from the abdominals as perpendicular to the torso. The free-body diagrams at two different points in the motion are provided.

2. A person is doing a sit-up (lie on their back and raise their torso up while keeping their lower body stationary). Use the hips as a pivot point and imagine their upper body stays rigid and straight throughout the motion. The person has a mass of m = 31 kg and lifts themselves with a constant speed. The center of mass of the torso is r, = 31 cm from the hip and the abdominal muscles apply a force r2 12 cm from the hip. Approximate the direction of the force from the abdominals as perpendicular to the torso. The free-body diagrams at two different points in the motion are provided.

College Physics

11th Edition

ISBN:9781305952300

Author:Raymond A. Serway, Chris Vuille

Publisher:Raymond A. Serway, Chris Vuille

Chapter1: Units, Trigonometry. And Vectors

Section: Chapter Questions

Problem 1CQ: Estimate the order of magnitude of the length, in meters, of each of the following; (a) a mouse, (b)...

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Question 8