What is the force required to move a wood object weighing 45,000 lbs resting on a level concrete surface?

To determine the force required to move a wood object weighing 45,000 lbs resting on a level concrete surface, it is essential to understand the concepts of static friction and the coefficient of friction between the wood and concrete. The force required to initiate movement is influenced primarily by these factors.

The correct answer indicates that a force of 20,250 lbs is required. This value is derived by applying the formula for calculating the force of friction, which is typically the product of the coefficient of friction and the normal force (in this case, the weight of the wood object). For dry concrete, the coefficient of static friction might average around 0.45. By applying this coefficient to the weight of the object:

Force = Coefficient of Friction × Weight Force = 0.45 × 45,000 lbs = 20,250 lbs

This calculation shows how significant the coefficient of friction is when assessing the force needed to start moving an object. In contrast, the other choices do not align with this calculation and do not reflect the correct application of the principles involved in understanding frictional forces on a level surface. Hence, the determination of 20,250 lbs as the required force effectively illustrates the relationship between weight and friction in practical applications