Determine maximum mechanical advantage, Mechanical Engineering

Determine maximum mechanical advantage:

For a lifting machine 15 N effort is needed to raise a load of 70 N with an efficiency equal to 60%, and 25 N effort is needed to lift a load of 1300 N. Find out the law of machine. What shall be the effort required to raise a load of 1000 N? Determine maximum mechanical advantage and the maximum efficiency.


Given :

Effort P1 = 15 N, and load W1 = 700 N

 Effort P2 = 25 N, and load W2 = 1300 N

Let m be the gradient and C be the intercept on y-axis. The law of machine can be expressed as :

P = m W + C    ----------- (a)

Substituting for P and W in Eq. (a), we obtain:

15 = m 700 +  C           --------- (b)

and      25 = m 1300 + C          ------------ (c)

Subtracting Eq. (b) from Eq. (c),

10 = 600 m,   or m =  10/600  =  1 /60

Substituting m in Eq. (b)

15 = (1/60) × 700 + C

or         C = 15 - (70/6) = 3.33

Substituting values of m and C, we obtain the law of machine as follows :

P = (W /60) + 3.33          ----- (d)  Ans

When load       W = 1000 N

P = (1000 /60 )+ 3.33 = 19.99 N

Maximum Mechanical Advantage

 Max. M. A. = 1/ m =   1/ (1/60) =60        Ans.

 Maximum Mechanical Efficiency

Max. η =1/(m × VR) = 60               Ans.

For 15 N effort to lift a load equal to 700 N,

M. A. = 700/15 = 46.66

Therefore, 0.6 = 46.66 /VR

 or,       V. R. = 46.66/0.6  = 77.77

Therefore,       Max. η = 1 / (m × VR)

= 60/77.77 = 0.77 or 77% Ans.

Posted Date: 1/29/2013 7:47:30 AM | Location : United States

Related Discussions:- Determine maximum mechanical advantage, Assignment Help, Ask Question on Determine maximum mechanical advantage, Get Answer, Expert's Help, Determine maximum mechanical advantage Discussions

Write discussion on Determine maximum mechanical advantage
Your posts are moderated
Related Questions
Computers control system in flexible manufacturing system

Mash stitch welding An overlap of about 1.15 mm is kept and then the plates are squeezed flash by application of pressure at hot condition.  Mash stitch welding is used in the

Find out the friction force: The cord passes over a massless and frictionless pulley, carrying a mass M 1 at one end and wrapped around a cylinder of mass M 2 which rolls on

Compute the force in the rod: A rod ABC rotating at 20 rpm about a vertical axis through A, supports a ball of mass 10 kg at its lower end. It is fixed in position by the rod

Evaluate the motion of system: Q : Block A and B are connected by a rigid horizontally bar planed at each end are placed on the inclined planes as shown in the figure giv

TERMINOLOG Y: 1 .     Top dead and Bottom dead Centre: These are 2 extreme positions between which the piston reciprocates inside the cylinder. TDC and BDC have relevance

Upward Compatibilityof IGES Upward Compatibility : The need for generations of processors to parse files compliant with earlier versions of IGES thwarted the breadth and rate o

Evaluate Force to slide the body over the surface: A body having weight 100N rests on rough horizontal surface (µ = 0.3) and is acted upon by a force applied at an angle of 3

construction and working of michelsons interferometer

WIRE-FRAME MODELS  The wire-frame model is perhaps the oldest way of representing solids. According to this model, any solid is represented by its edges and vertices. A wire-fr