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.


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
Explain in detail about the Large excavations Large excavations required for construction of rafts may need dewatering, depending on the ground water flow and the choice of  a

Derive the mathematical expression for heat transfer and temperature distribution through infinite long fin?

Coil: A coil is used in ignition system to increase the voltage supplied by the battery or magneto. Coil

The resultant of four vertical forces is a couple moment 30 Nm acting counter clockwise. Three of the four forces are shown in fig given below. Evaluate the fourth force.

A Perspex tank ure 1), which has parallel sides for the top part of its height and a 'V' shaped section for the bottom part and a constant width throughout, is used as a receptacle

#queConsider laminar flow in a circular tubewith a fully developed velocity profile.Let the heat be added at a constant rate along the tube from x+ =0 to x+ =0.10 . Thereafter ,

Q. Flanged pressure vessel nozzles? The Designer is responsible for ensuring that the facings, bolt circle, number of bolts, and size of bolts of vessel nozzles, match the mati

A triangle ABC with vertices A (30,20), B(90,20), C(30,80) is to be scaled by a factor of 0.5 about a point X(50,40). Calculate :- (i) The composite transformation matrix; and

Question: (a) Describe stochastic printing and provide three benefits of this printing technique. (b) Though offset printing is the most common form of mass printing and pub

What is the limition of kkleins constraction?