calculate the maximum wheelbarrow load able to be lifted by an effort of 75 n

Force applied to the outside of the wheel causes a greater force to be applied to the rope that is wrapped around the axle. The difference is that the effort arm can rotate in a complete circle around the fulcrum, which is the center of the axle. The simple machine shown in Figure 9.9 is called a wheel and axle. In another type of lever, the fulcrum is at the end of the lever and the load is in the middle, as in the design of a wheelbarrow. Examples of this type of lever are baseball bats, hammers, and golf clubs. This results in a smaller force acting over a greater distance at the end of the resistance arm. Some levers exert a large force to a short effort arm.

Since both have different weights, they will never be in balance.Both children sit at equal distance from the fulcrum.The heavier child sits farther from the fulcrum.The heavier child sits closer to the fulcrum.How do they position themselves with respect to the pivot point (the fulcrum) so that they are balanced? Two children of different weights are riding a seesaw. The equation for IMA is shown in Figure 9.8(b). The ideal mechanical advantage, IMA, is the mechanical advantage of a perfect machine with no loss of useful work caused by friction between moving parts. The mechanical advantage is a number that tells us how many times a simple machine multiplies the effort force. The triangular pivot is called the fulcrum the part of the lever between the fulcrum and F e is the effort arm, L e and the part to the left is the resistance arm, L r. The effort force, applied at F e, lifts the load (the resistance force) which is pushing down at F r. Figure 9.8(b) shows the how a lever works mathematically. In Figure 9.8(a), the worker uses a type of lever to exert a small force over a large distance, while the pry bar pulls up on the nail with a large force over a small distance. Let’s examine how this works in practice. The down side is that you must exert the force over a greater distance, because the product of force and distance, f d, (which equals work) does not change.

In most cases, a simple machine is used to reduce the amount of force you must exert to do work.

So, why is a simple machine useful? Although it cannot change the amount of work you do, a simple machine can change the amount of force you must apply to an object, and the distance over which you apply the force. A machine cannot increase the amount of energy you put into it. Why can’t simple machines change the amount of work that you do? Recall that in closed systems the total amount of energy is conserved. Simple machines make work easier, but they do not decrease the amount of work you have to do.

Calculate the maximum wheelbarrow load able to be lifted by an effort of 75 n