Question

2. A lever has efficiency 60% and mechanical advantage 4, then
(i) Calculate effort required to lift 1000 N load. [250 N] (ii
(ii) Calculate velocity ratio of the lever. [VR = 6.66]
(iii) Find out output work to turn load up to 20 m. [20,000 Nm]
1:0​

Answer 1

Answer:

(i) Effort = 250 N

(ii) Velocity ratio = 6.667

(iii) work output = 20 000 Nm

Explanation:

Given: efficiency = 60%, mechanical advantage = 4.

(i) Mechanical advantage = $\frac{Load}{effort}$

Load = 1000 N

⇒ Effort = $\frac{Load}{Mechanical advantage}$

             = $\frac{1000}{4}$

             = 250 N

Effort = 250 N

(ii) Efficiency = $\frac{Mechanical advantage}{velocity ratio}$ x 100%

Velocity ratio = $\frac{Mechanical advantage}{Efficiency}$ x 100%

                      = $\frac{4}{60}$ x 100

                      = 6.667

Velocity ratio = 6.667

(iii) Work output = Load x distance moved by load

                         = 1000 x 20

                         = 20 000

Work output = 20 000 Nm