Force to Lift 10 Bags of Soil (185N each)

[halo9909]

Homework Statement

Ten bags of top soil, each weighing 185 N, are placed on a 2.40-m long sheet of wood. They are stacked 0.50 m from one end of the sheet of wood, as shown below. Two people lift the sheet of wood, one at each end. Ignore the weight of the wood, how much force must each person exert?

Homework Equations

none

10*185=1850N so that would be the total being liften since the wood is ignored
From there I am stuck as to do what http://img120.imageshack.us/img120/6727/p827rs8.th.gif

 

[LowlyPion]

Treat it as a moment arm about one end or the other. Your choice.

The weight times the distance away from where you choose and the force times the length of the board must match shouldn't they? Since you know the total weight then you know the sum of the lifting forces must equal that.

 

[thomate1]

I would approach this problem by first determining the overall weight of the system. As you correctly calculated, the total weight of the 10 bags of soil is 1850 N. However, we also need to take into account the weight of the wood, which we can assume to be negligible compared to the weight of the soil bags.

Next, I would consider the distribution of this weight on the sheet of wood. Since the bags are stacked 0.50 m from one end, we can assume that the center of mass of the system is located at a distance of 1.20 m from the end where the bags are stacked. This means that each person would need to exert a force equal to half of the total weight (925 N) to lift the sheet of wood and the bags.

However, this is a simplified calculation and does not take into account the distribution of weight within each bag of soil. If the bags are not evenly filled, the center of mass may be located at a different distance from the end of the sheet of wood, and the forces required to lift the system would vary accordingly.

Furthermore, it is important to consider the angle at which each person is lifting the sheet of wood. If they are not lifting it at a perpendicular angle, the forces required to lift the system would be greater due to the influence of the weight's component in the direction of lift.

Overall, it is important to carefully consider the distribution of weight and the angle of lift in order to accurately determine the forces required to lift the 10 bags of soil. I would also recommend conducting experiments to test the accuracy of these calculations and to identify any other factors that may affect the forces required for this task.