Q25DQ A horse is hitched to a wagon. S... [FREE SOLUTION]

91影视

University Physics with Modern Physics

Hugh D. Young, Roger A. Freedman

Physics

14th edition Edition 路 1596 pages

ISBN: 9780321973610

Chapter 1: Q25DQ (page 123)

A horse is hitched to a wagon. Since the wagon pulls back on the horse just as hard as the horse pulls on the wagon, why doesn鈥檛 the wagon remain in equilibrium, no matter how hard the horse pulls?

Short Answer

Expert verified

The wagon will not be in equilibrium because equal and opposite forces, as stated in the third law, act on two different bodies.

Step by step solution

Define the Newton’s 3rd law

The first body exerts a force on the second body, and the second body exerts an equal and opposite force on the first body.

${\overset{鈫�}{F}}_{12} = - {\overset{鈫�}{F}}_{21}$

This action and reaction of forces act on different bodies. These forces act on each other as long the objects are in contact.

Determine the conclusion for the given case:

In the given case, the horse pulls on the wagon, and the wagon pulls back on the horse with the same pull. Remember that action and reaction force act on two different bodies. For the wagon to be in equilibrium, a force must be equal and opposite to the horse鈥檚 pull. But there is no such force and the horse pulling the wagon is the only force on the wagon. Hence the wagon will not be in equilibrium when the horse pulls it harder.