Question

A walnut can be broken by applying a direct force of 50 kgf. If the walnut is placed in a nut cracker, the length of whose handle is 18 cm and nut is placed 2 cm from the pivot, calculate the minimum force required to crack the nut.

Answer 1

Nutcracker is a lever of second order.

Given: Load arm (d) = 2 cm

∴ Effort arm (D) = 18 cm

Load (L) = 50 kgf, Effort (E) = ?

Now, Load × load arm = Effort × effort arm

50 kgf × 2 cm = Effort × 18 cm

\[ \therefore\ \text{Effort} = \dfrac{50\ \text{kgf} \times 2\ \text{cm}}{18\ \text{cm}} \]

\[= \frac{100}{18}\ \text{kgf} \]

= 5.55 kgf