Determine tension in the rope - motion of lift, Mechanical Engineering

Determine tension in the rope:

An elevator cage of mineshaft, weighing 8KN when, is lifted or lowered by means of wire rope. Once man weighing 600N entered it and lowered with the uniform acceleration such that when the distance of 187.5m was covered, velocity of cage was 25m/sec. determine tension in the rope and the force exerted by man on the floor of cage.

Sol: Given data;

Weight of empty lift WL  = 8KN = 8000N

Weight of man Wm  = 600N

Distance covered by lift s = 187.5m

Velocity of lift after 187.5m v = 25m/sec

Tension in rope T = ?

Force exerted on man Fm  =?

Apply the relation v2  = u2  + 2as, for finding acceleration

(25)=0 + 2a (187.5) a =1.67m/sec2                                                                           ...(i)

Cage moves down only when WL + Wm  >T

Net accelerating force = (WL  + Wm)- T

Using the relation F = ma, then (WL + Wm)- T = ma = [(WL + Wm)/g]a(8000 + 600) - T = [(8000+ 600)/9.81] X 1.67

T = 7135.98N                                                   .......ANS

Calculation for the force exerted by the man. Consider the weight of man only, Fm - Wm = maFm  - 600 = (600/9.81) X 1.67Fm  = 714.37N

 

2048_Determine tension in the rope.png

As Newton's third law states that the force of action and reaction between interacting bodies are equal in magnitude but opposite in direction and have the same line of action.

That is, Force exerted by the man = F = 714.37N                                        ........ANS

Posted Date: 10/19/2012 7:48:46 AM | Location : United States







Related Discussions:- Determine tension in the rope - motion of lift, Assignment Help, Ask Question on Determine tension in the rope - motion of lift, Get Answer, Expert's Help, Determine tension in the rope - motion of lift Discussions

Write discussion on Determine tension in the rope - motion of lift
Your posts are moderated
Related Questions
A Common Cell Control Software  In this section, fine and common implemented cell control software are developed, that is based upon a transition table, to show the restriction

Calculate root of equation 3x = 100 cosx + 1 by Newton Raphson method correct to three decimal places Calculate root of equation xe x = cosx by Secant method correct to three d

Q. Flange Facing and Surface Finish? Raised face flange facings are preferred. Flat face flanges to be used only when mating with like equipment (fabricated from brittle mat

draw the projection of pentagonal pyramid have 30 mm edge and axis 50 mm long having base on hp and an edge of the box parallel to vp

Organisation set-up: The civil engineering department of the Railways is responsible for the maintenance of railway lines. The maintenance organisation consists of Chief Engi

Explain End Relief Angle It is the angle between the plane perpendicular to base and end flank. The angle prevent\s the cutting tool from rubbing against the job where as if th

Shielded Metal Arc Welding   Single pass fillet welds upto ¼" (6.4 mm) maximum and ¼" groove welds made with a single pass or a single pass each side, may be made by using a

Use s of Carnot Cycle: 1. It helping us to appreciate what factors is desirable in the design of practical cycle; namely a maximum possible temperature range. 1 maximum p

Necessity of Cooling System To prevent the engine from excessive heating. To avoid the piston seizure due to thermal expansion. To prevent burning of lubricant a