Question

In four pulley system a load of 800n is overcome .If MA is 3 . Calculate the effort applied VR and efficiency

Answer 1

effort = 266.66N

VR and efficiency are 8 and 37.5% respectively.

Step-by-step explanation:

Given data: four pulley system, load = 800 N, Mechanical advantage MA = 3

we have to calculate both velocity ratio and efficiency

If there are n movable pulleys connected to a fixed pulley then

VR =
`2^(n)`

In the given question there are 4 pulleys in which one must be fixed and 3 movable

Therefore, VR = 2^3 = 8

Also, MA = Load/ effort

⇒ 3= 800/effort

⇒ effort = 266.66N

Also we know that

Efficiency = MA/VR

⇒Efficiency = 3/8 = 37.5%

Therefore, VR and efficiency are 8 and 37.5% respectively.