Advertisements
Advertisements
Question
Select the correct alternative:
A pulley is used because of it
Options
has the mechanical advantage greater than one
has 100% efficiency
helps to apply the force in a convenient direction
requires more effort to raise a less load.
Advertisements
Solution
helps to apply the force in a convenient direction
APPEARS IN
RELATED QUESTIONS
A block and tackle system has V.R. = 5.
Draw a neat labeled diagram of a system indicating the direction of its load and effort
What is a gear system ?
Give reason for the following:
The lower block of a block and tackle pulley system must be of negligible weight
Give reason for the following:
The efficiency of a pulley is always less than 100%
Name a machine which is used to:
change the direction of force applied.
Fig shown a block and tackles system of pulleys used to lift a load.
(i) How many strands of tackle are supporting the load?
(ii) Draw arrows to represent tension in each stand.
(iii) What is the mechanical advantage of the system?
(iv) When load is pulled up by a distance 1 m how far does the effort end move?
A block and tackle system of pulleys has a velocity ratio of 4.
- Draw a labelled diagram of the system indicating clearly the points of application and directions of load and effort.
- What is the value of the mechanical advantage of the given pulley system if it is an ideal pulley system?
A man raises a load of 360 kgf using a block and tackle system of 3 pulleys. If the efficiency of the pulley system is 60%, what effort is applied by the man?
A boy lifts a load of 40 kgf through a vertical height of 2m in 5s by using a single fixed pulley when he applies an effort of 48 kgf. Calculate:
(i) the mechanical advantage, and
(ii) the efficiency of the pulley. Why is the efficiency of the pulley is not 100%?
(iii) the energy gained by the load in 5s, and
(iv) the power developed by the boy in raising the load.
A pulley is a machine made up of a ______.
