What is the effort required if the MA is 7 and the load is 45 N?

Given,

• Mechanical advantage = 7
• Load = 45 N

As,

$\text {Mechanical Advantage (M.A.)} = \dfrac{\text {Load}}{\text {Effort}}\\[1em] \Rightarrow \text {Effort} = \dfrac{\text {Load}}{\text {M.A.}}\\[1em] = \dfrac {45}{7}\\[1em] \Rightarrow \text {Effort} = 6.43\ \text N$

So, the required effort is 6.43 N.