A worker pulling a crate applies a force at an angle of 30° to the horizontal, as shown in Figure 4.22. What is the magnitude of the minimum force he must apply to move the crate? (Before looking at the solution, would you expect that the force needed in this case would

be greater or less than that in Example 4.10?) THINKING IT THROUGH. Since the applied force is at an angle to the horizontal surface, the vertical component will affect the normal

force. (See Figure 4.11.) This change in the normal force will, in turn, affect the maximum force of static friction.