Find out the effort required to run this machine, Mechanical Engineering

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         FP  = 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







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
Related Questions
Determine the percentage savings in the material: A hollow shaft containing an inside diameter 0.5 times the outer diameter is to replace the solid shaft of the similar materi

The purpose of this section of your assignment is to familiarise yourself with the basic FE theory and relate it to the fundamental concepts of stress and strain calculations in en

i wanna know is production job is best or marketing after doing btech

INTRODUCTIO : In Motorcycle Servicing, we studied about servicing of a motorcycle. Here, you will study about the detailed procedures for motorcycle service and maintenance. The s

Discover the suitable diameter of the shaft: A shaft is required to fail while the torque on the shaft is 20 kN-m. Discover the suitable diameter of the shaft of the modulus o

Engineering Plastics In this time this has become clear to know, the plastics are utilized as engineering materials for machine parts, casting and bodies and for structure mai

how to prove that heat and work is path function?

Concept of plane stress: Define the concept of plane stress. Sol.:   In cubical element of strained material is acted on by stresses acting on only 2 pairs of parallel plane

fms computer control system

Tunnels: Tunnels become unavoidable for negotiating hills, where detours are costly. The tunnels in rock are not lined, but those in loose strata require a lining of cement c