Which of the following actions requires muscular force?
Reading a book
A body suspended by a spring
The pushing of a door to close it
Falling of an apple from a tree
Pushing a door requires force that is caused by the action of muscles.
Which of the following is not an example of muscular force ? (a) a porter carrying a load on a wheel-barrow. (b) an apple falling from a tree. (c) a child riding a bicycle. (d) a person drawing water from a well.
An apple falling from a tree is an example of: