A man is using a fishing rod to catch fish in figure 1. Figure 2 is a simplified diagram of figure 1 with the forces and distances.

Calculate the force F, in figure 2.

Explanation:

Remark

In general, these 3rd class levers are very inefficient. Because the force distance is smaller than the load distance, you need to pull upward with more force that the weight of the load. So whatever the load is, the force is going to be much greater.

The distances are always measured to the pivot unless you are asked something specific otherwise.

Givens

F = ?

weight = 6N

Force Distance = F*d = 0.5 m

Weight Distance =W*d1 = 2 m

Formula

F*Fd = W*Wd

Solution

F*0.5 = 6 * 2            Divide by 0.5

F = 12/0.5

F = 24 N upwards

the body's situation won't change the forces are equal opposit and on the same body