Question

The diagram shows the use of a lever. If FA = 10 cm, AB = 500 cm, calculate the minimum effort required to lift the load.

• A. 1550 N
• B. 2000 N
• C. 2550 N
• D. 5100 N

Answer 1

The correct option is C

2550 N

Given: Effort arm (FA) = 10 cm

Load arm (BF) = FA + AB = 500 + 10 = 510 cm

Mechanical advantage (MA) is defined as the ratio of the load overcome to the effort applied or the ratio of effort arm to the load arm i.e.,

Mechanical Advantage = $\frac{\text{Load(L)}}{\text{Effort (E)}}$ = $\frac{\text{Effort arm}}{\text{Load arm}}=\frac{10}{510}=\frac{1}{51}$

$\therefore$ $\frac{\text{Load (L)}}{\text{Effort (E)}}=\frac{1}{51}$

$\Rightarrow$ $\frac{50}{\text{E}}=\frac{1}{51}$

$\Rightarrow$ Effort (E) = 50 x 51 N = 2550 N