To lift up any little objects, a hoist goes about as a heavy lifting device. With the assistance of a chain or a rope, a crane pulls a heavy object easily. The medium of lifting a thing is either a chain or a wire rope. You can get a wide assortment of cranes from the market to meet your need for lift machines.

Effort (Force) = 100 N / 2 = 50 N.

Law of the machine. It is the relationship between the load lifted (W) and the effort applied (P). It is given by the equation, P = m.W+C. where. m = A constant (called coefficient of friction) which is equal to the slope of the line AB as shown in Fig.

Lifting equipment is any work equipment for lifting and lowering loads, and includes any accessories used in doing so (such as attachments to support, fix or anchor the equipment). Examples of lifting equipment include: overhead cranes and their supporting runways. patient hoists.

Machines which are used to lift a load are governed by the “Law of machines”, which states that the effort to be applied on the machine (p) is related to the weight (w) which it can lift as – p = mw + c Where m and c are positive constants which are characteristics of the machine.

Answer. LAW OF MACHINE: called as Law of a machine. i.e. P = mW + C.

When a machine is not capable of doing some work in the reverse direction even on removal of effort, it is called as irreversible machine or non-reversible machine or self locking machine. Condition for Irreversible Machine: The efficiency of the machine should be less than 50%.

Explanation: No machine is free from the effects of gravity, and even with wonderful lubrication, friction always exists. The energy a machine produces is always less than the energy put into it (energy input). That is why 100% efficiency in machines shall not be possible.

Answer. The definition of a perfect machine states that a perfect machine should be 100% efficient which means the 100% of the energy input should be transformed into work output. For these reasons,we cannot expect perfect machines in the real life situations.

Machine Efficiency Efficiency is the percent of work put into a machine by the user (input work) that becomes work done by the machine (output work). The output work is always less than the input work because some of the input work is used to overcome friction. Therefore, efficiency is always less than 100 percent.

Answer: A machine cannot be 100 percent efficient because output of a machine is always less than input. A certain amount of work done on a machine is lost to overcome friction and to lift some moving parts of the machine.

A lever is a simple machine made of a rigid beam and a fulcrum. The effort (input force) and load (output force) are applied to either end of the beam. The fulcrum is the point on which the beam pivots. When an effort is applied to one end of the lever, a load is applied at the other end of the lever.

In a first class lever, the fulcrum is located between the input force and output force. In a second class lever, the output force is between the fulcrum and the input force.

Levers can be used so that a small force can move a much bigger force. This is called mechanical advantage. In our bodies bones act as lever arms, joints act as pivots, and muscles provide the effort forces to move loads.

There are many examples of third class lever systems, including both flexion and extension at the knee joint. During flexion at the knee, the point of insertion of the hamstrings on the tibia is the effort, the knee joint is the fulcrum and the weight of the leg is the load.

First class levers have the fulcrum between the load and effort. This distinguishes first class levers from second and third class levers, where the load and effort are both on one side of the fulcrum. The load is the pivot point of a lever. The first class lever is the most common lever in the human body.

The first class lever is one of three classes of levers and is one possible arrangement of muscles, bones, and joints found in the human body. While less common in the body than second and third class levers, the first class lever system is found in the neck at the atlanto-occipital joint and in the elbow joint.

The liver is a large, meaty organ that sits on the right side of the belly. Weighing about 3 pounds, the liver is reddish-brown in color and feels rubbery to the touch. Normally you can’t feel the liver, because it’s protected by the rib cage. The liver has two large sections, called the right and the left lobes.

If we extend the elbow, moving the hand upwards against resistance, the active lever is a first-class lever because the fulcrum is between the effort from the triceps and the load (Figure 1, B2).

the disadvantage of the first class lever is the fulcrum lies on more effort or more force.

First-class levers have a considerable practical advantage over the other types of levers. They convert a downward moving force into a lifting force. This means that you can always augment your ability to lift a load across a teeter-totter style lever simply by using the force of gravity.

Second class levers always provide a mechanical advantage. The effort is always less than the load, and always moves farther than the load. Actually, if you look at the lug wrench in detail, the point that doesn’t move (the fulcrum) is in between different parts of the load- the different sides of the nut.

In one, called a second-class lever, the resistance force lies between the effort force and the fulcrum. A nutcracker is an example of a second-class lever. The fulcrum in the nutcracker is at one end, where the two metal rods of the device are hinged together.

In summary, in a first class lever the effort (force) moves over a large distance to move the load a smaller distance, and the fulcrum is between the effort (force) and the load. As the ratio of effort (force) arm length to load arm length increases the mechanical advantage of a first class lever increases.