Find out the effort required to run this machine:

The efficiency of a machine is 75% while an effort of 20 N is required to lift a load of 160 N. Compute the velocity ratio and frictional force of the machine in terms of effort and load. What is the law of machine if frictional resistance of the machine is constant? Find out the effort required to run this machine at a load of 200 N.

Solution

Given :

Efficiency (η) = 75% Effort (P) = 20 N

Load lifted (W) = 160 N

Mechanical Advantage (M A) = 160 /20 = 8

Velocity Ratio (V R) = MA/ η = 8.0/ 0.75

                                                   = 10.67         Ans.

Frictional force in terms of load (FW) = P × V R - W

or         FW = 20 × 10.67 - 160

                         = 53.4 N

Frictional force in terms  of effort (F _P ) = P -  (W/ V R)

or         F_P  = 20 - (160 /10.67) = 5 N

 The effort needed to overcome friction is 5 N, which is constant. In the law of machine, the factor C is constant which is equal to effort required when load lifted is zero.

Therefore,       C = FP = 5 N

Therefore, law of the machine can be written as :

                    P = m W + 5

For       P = 20 N and W = 160 N

20 = 160 m + 5

or         m = (20 - 5) /160=15/160 =  3 /32

Substituting for m, the law of machine is given by :

P =  (3/32) W + 5                         Ans.

For load           W = 200 N

P =  (3 /32) × 200 + 5 = 23.75 N            Ans.

Posted Date: 1/29/2013 7:48:00 AM | Location : United States

Ask an Expert

Related Discussions:- Find out the effort required to run this machine, Assignment Help, Ask Question on Find out the effort required to run this machine, Get Answer, Expert's Help, Find out the effort required to run this machine Discussions

Write discussion on Find out the effort required to run this machine
Your posts are moderated

Write your message here..

Related Questions

What is tantalum, Q. What is Tantalum? Tantalum is one of the most corr... Q. What is Tantalum? Tantalum is one of the most corrosion-resistant metals known. However, the high cost of tantalum has limited its commercial use as an all-purpose corrosio

Flange assembly with torque measurement, Q. Flange Assembly with Torque Mea... Q. Flange Assembly with Torque Measurement? Select the proper bolts and gasket for the intended service. Use only new, undamaged gaskets. Lubricate the bolt threads and nut

Submerged arc welding, SUBMERGED ARC WELDING The optimum performance of w... SUBMERGED ARC WELDING The optimum performance of welded vessels and structures in service have led to the full exploitation of automatic welding processes. This arc welding is on

Thermodynamics., First law of thermodynamics applied to flow process First law of thermodynamics applied to flow process

Find out the angle of force - center of wheel, Find out the angle of force:... Find out the angle of force: Q: A uniform wheel having 60 cm diameter weighing 1000 N rests against rectangular obstacle   15 cm high. Find least force required which when ac

Steam table - thermodynamics, Steam table - Thermodynamics: Sol.: St... Steam table - Thermodynamics: Sol.: Steam table offers various physical data regarding the properties of saturated water and steam. This table is very helpful in solving the

Modulus of elasticity, Explain Young's Modulus or Modulus of elasticity? ... Explain Young's Modulus or Modulus of elasticity? Sol. : It is ratio between tensile stress and tensile strain or compressive stress and compressive strain. It can be denote

Ed, how to draw projections of planes how to draw projections of planes

Kinematics and Dynamics of Machinery, I have Four (4) questions related to ... I have Four (4) questions related to Kinematics and Dynamics of Machinery . I need them exactly after 30 hours. Thanks and please do let me know.

Spanners tool and equipment , Spanners: These are used to tighten and loos... Spanners: These are used to tighten and loosen nuts and bolts. These are made according to standard nut and bolt sizes and in vanadium steels. The following types of spanner are u