(a) How many strands of tackle are supporting the load?
(b) Draw arrows to represent tension T in each strand.
(c) What is the mechanical advantage of the system?
(d) When load is pulled up by a distance 1 m, how far does the effort end move?
(e) How much effort is needed to lift a load of 100 N?

Solutions –

(a) Total strands of tackle supporting the load are four in number.

(b)

(c) Expression for the mechanical advantage of the system is

M.A. = Load / Effort = 4T / T

M.A. = 4

(d) The effort end will move a distance ‘d’ when load is pulled up by a distance 1 m, which is

d = 1 × 4 = 4m

(e) Using the expression for the mechanical advantage of the system, we have

M.A = Load / Effort

4 = 100 / effort

or, we can write – Effort = 100 / 4

Effort = 25 N