Elston attaches a spring scale to a box and pulls it across the floor. He then places a book in the box and pulls it in the same distance with the same effort. How does the force change after the book is placed in the box?

Question

Elston attaches a spring scale to a box and pulls it across the floor. He then places a book in the box and pulls it in the same distance with the same effort. How does the force change after the book is placed in the box?
Responses

it will increase
it will increase

it could increase or decrease depending on the weight of the book
it could increase or decrease depending on the weight of the book

it will decrease
it will decrease

it could increase or decrease depending on the weight of the box

GPT-4o mini · Answer

The correct response is: **it will increase**. When Elston places a book in the box, he is increasing the total weight of the box. To pull the box across the floor with the same distance and effort, the force exerted by the spring scale must increase to overcome both the additional weight of the book and any friction between the box and the floor. Therefore, the force measured by the spring scale will increase.