Question

Diagram alongside shows a nut cracker.

1. What kind of lever is nutcracker?
2. Copy the diagram on it show the line of action of force for (i) effort, (ii) load.
3. What is the mechanical advantage of this lever?
4. Calculate the resistance offered by the nut, if an effort of 300 N is sufficient to crack it.

Answer 1

a. A nutcracker is a second-class lever because the load (the nut) lies between the fulcrum (the hinge) and the effort (applied at the handles).

b. 

c. Mechanical advantage of a lever = effort arm ÷ load arm.

\[ \text{M.A.} = \frac{\text{Effort arm}}{\text{Load arm}} = \frac{70\ \text{cm}}{40\ \text{cm}} = 1.75 \]

d. \[ \text{M.A.} = \frac{\text{Load}}{\text{Effort}} \]

\[ \text{Load} = \text{M.A.} \times \text{Effort} \]

\[ \text{Load} = 1.75 \times 300\ \text{N} = 525\ \text{N} \]

Therefore, the resistance offered by the nut is 525 N.