A machine with V.R 5 require 10000J of work to raise a load of 500N through a vertical distance of 1.5m. find the efficiency and the mechanical advantage M.A of the machine.
So efficiency = 75%
To solve M.A
Where V.R = 5 , efficiency = 75%
M.A = 3.75
Simple machine question and answers 5
Simple machine are classified in to three. Name them
They are First order, second Order and third order levers.
Simple machine question and answer 6
A block and tackle consisting of 5 pulleys is used to raise a load of 400N through height of 10m. if the work done against friction is 1000J, calculate
(a). the work done by the effort
(b). the efficiency of the machine
(c). the effort applied
(a). the work done by the effort is equal to work done against friction + work done in raising the load
ie 1000 + 400 x 10 = 5000N
Efficiency = 80%
(c). Note that for block and tackle that has 5 pulleys the V.R = 5 (velocity ratio)
Where V.R = 5, efficiency = 80%
Effort = 100N
Simple machine question and answer 7
(7). What is the velocity ratio of an inclined plane of length 6m, if the higher end is 2m above the ground ? if the efficiency of this machine used is 60%. Calculate the mechanical advantage M.A.
Where Ɛ=60% and V.R = 3
Simple machine question and answers 8
(8). The pitch of the screw of a screw jackof 0.5cm. When used to raise a load, the handle turns through a circle of radius 40cm. What is the mechanical advantage of the jack if its efficiency is 25%? (π =3.14)
First let find the V.R
Where Pitch is the distance between consecutive threads =0.5cm, and a = the radius of the thread=40cm.
Simple machine question and answers 9
. A wheel and axel is used to raise a man of weight 700N by application of effort 200N. If the radii of the wheel and axle are 400mm and 100mm respectively, determine the efficiency of machine.
(1). An inclined plane of 300 is used as simple machine . What is it Velocity Ratio. V.R?
(2). The pitch of a screw Jack is 0.5cm. The arm is 50cm long and its mechanical advantage is 250. What is its efficiency? ( take π = 3.142)