Chapter 7, Problem 7.7CQ

(a)

To determine

Whether the work is positive or negative if a chicken scratching the ground.

(b)

To determine

Whether the work is positive or negative if a person is studying a book.

(c)

To determine

Whether the work is positive or negative if a crane lifts a bucket of concrete.

(d)

To determine

Whether the work is positive or negative if a crane lift a bucket and the gravitational force act on the bucket.

(e)

To determine

Whether the work is positive or negative if the leg muscles of a person in the act of sitting down.