Advertisements
Advertisements
Question
The diagram below shows an arrangement of three pulleys A, B, and C. The load is marked as L and the effort as E.
- Name the Pulleys A, B, and C.
- Mark in the diagram the directions of load (L), effort (E) and tension T1 and T2 in the two strings.
- How are the magnitudes of L and E related to the tension T1?
- Calculate the mechanical advantage and velocity ratio of the arrangement.
- What assumptions have you made in parts (c) and (d)?

Advertisements
Solution
(a) Pulleys A and B are movable pulleys. Pulley C is a fixed pulley.
(b)

(c) L = 4T1; E = T1
(d) M.A. = `L/E`
M.A. = `(4T_1)/T_1`
M.A. = 4
V.R. = `(4d)/d = 4`
(e)
- There is less weight on pulleys A and B.
- There's no friction at all between the axle and the pulleys.
APPEARS IN
RELATED QUESTIONS
A boy uses a single fixed pulley to lift a load of 50 kgf to some height. Another boy uses a single movable pulley to lift the same load to the same height. Compare the effort applied by them. Give a reason to support your answer.
Draw a neat labelled diagram showing a pulley being used to lift a load. How are load and effort related in an ideal situation?
Explain how a gear system can be used to obtain Change in direction of rotation. Given one example.
Name the type of single pulley that can act as a force multiplier. Draw a labelled diagram of the pulley mentioned by you.
A block and tackle pulley system has a velocity ratio 5. Draw a labelled diagram of this system. In your diagram, indicate clearly the points of application and the directions of the load and effort.
Give reason for the following:
In case of a block and tackle arrangement, the mechanical advantage increases with the increase in the number of pulleys.
A pulley system has a velocity ratio 3. Draw a diagram showing the point of application and direction of load (L), effort (E) and tension (T). It lifts a load of 150 N by an effort of 60 N. Calculate its mechanical advantage. Is the pulley system ideal? Give reason.
What is a pulley?
A pulley is a machine made up of a ______.
Name the type of single pulley that has an ideal mechanical advantage equal to 2. Draw a labelled diagram of the pulley mentioned by you.
