Question

. A block and tackle system of pulleys is used to lift a load of 360kgf by applying an effort of 200kgf such that load is lifted to a height of 2m and effort is applied through a distance of 8m. Find MA and VR of the system. (a) MA = 3.6 and VR = 2 (b) MA = 2 and VR = 8 (C) MA = 1.8 and VR = 4 (d) MA = 4 and VR = 6 = 2 .​

Answer 1

Answer:

A block and tackle system of pulleys is used to lift a load of 360kgf by applying an effort of 200kgf such that load is lifted to a height of 2m and effort is applied through a distance of 8m.

Mechanical advantage = 1.8

Velocity ratio = 4

correct answer is option c.

Explanation:

Given,

Load = 360 kgf = 3530.39 N (Since 1 kgf = 9.80665 N)

Effort = 200 kgf = 1961.33 N

Mechanical advantage is the ratio of load and effort and it can be written as,

• M.A = $\frac{Load}{Effort}$ = $\frac{3530.39}{1961.33}$ = 1.8

Given,

Load distance ($d_{L}$) = 2 m

Effort distance($d_{E}$) = 8 m

Velocity ratio is given by the ratio of effort distance and load distance.

That is,  

Velocity ratio, $V R=\frac{\text { Distance of effort }\left(d_{E}\right)}{\text { Distance of load }\left(d_{L}\right)}$

• $V.R = \frac{8}{2} = 4$

 Thus option c is correct.