A force of 320kN acts perpendicular to a lever arm, at a distance of 4m from a point. What turning moment does the force produce about the point?

To find the turning moment, also known as torque, produced by a force acting at a distance from a point, you can use the formula:

[ \text{Torque} = \text{Force} \times \text{Distance} ]

In this scenario, a force of 320 kN is applied perpendicular to the lever arm, which is at a distance of 4 m from the point. Since the force is applied perpendicular to the lever arm, the formula simplifies to a direct multiplication of the force and the distance.

Calculating it:

[ \text{Torque} = 320 , \text{kN} \times 4 , \text{m} = 1280 , \text{kNm} ]

This indicates that the force produces a turning moment of 1280 kNm about the point. The unit kNm (kilonewton meters) is standard for measuring torque, emphasizing the significance of both the magnitude of the force and the distance from the pivot point in producing rotational motion.

The other options provided do not represent torque in the correct units or context related to the problem. Thus, the correct answer succinctly illustrates the concept of torque derived from a straightforward application of the fundamental physics