Final answer:
To find the resultant horizontal force on the crate, calculate Joan's horizontal force component and add it to John's eastward force. The vertical component is irrelevant for horizontal force calculation.
Step-by-step explanation:
To determine the resultant horizontal force on the crate, we must add the forces vectorially. John's force is strictly horizontal, pointing due east, with a magnitude of 185 N. Joan's force must be broken down into horizontal and vertical components. Since Joan's force is at a 30° angle north of east, the horizontal component (FJoan,x) can be found using cosine:
FJoan,x = 165 N × cos(30°)
The vertical component is not needed for the horizontal resultant force. Once we calculate FJoan,x, we sum it with John's force:
Fresultant,x = 185 N + FJoan,x
Performing the calculations will yield the total horizontal force on the crate.