Answer to Question #202480 in Physics for Benedict

Question

A boy pulls a nail from the wall with a string tied to a nail. The string is inclined at angle 60° to the wall. If the tension in the string is 4N, what is the effective force used in pulling the nail?

Answer 1

The effective force of pulling is the tension projected on the axis of the nail:

$$F=T\cos30°=3.49\text{ N}.$$