Question

Give an example of something we think of as work in everyday circumstances that is not work in the scientific sense. Is energy transferred or changed in form in your example? If so, explain how this is accomplished without doing work.

a) Lifting a backpack; no energy transfer
b) Holding a book; energy transfer occurs
c) Pushing a wall; energy converted to potential energy
d) Carrying groceries; energy transferred to the surroundings

Answer 1

Holding a book steady is an example where no scientific work is done despite the transfer of energy within the body, which is later dissipated as heat.

Step-by-step explanation:

An example of something that we often consider as work in our daily life but is not considered work in the scientific sense is holding a book steady in one's hand. In physics, work is defined as a force causing displacement; therefore, if there is no movement, no work is done scientifically.

While holding a book, there is no displacement of the book and hence no work done on the book, even though you may feel like you are exerting effort. However, your body is still expending energy to counteract the force of gravity, and this energy comes from metabolic processes converting chemical energy into the mechanical energy of maintaining muscle tension. This energy is ultimately released as heat to the surroundings, which represents a transfer of energy but not in the form of work on the book.