Question

A force of \(P = 100 \, N\) is applied at the ends of the pliers as shown in the figure. Neglecting friction, the force exerted by the upper jaw on the workpiece is ........ N (in integer).

Hint:

Pliers work as a pair of levers: \[ F_{jaw} = P \times \frac{L_{in}}{L_{out}} \] Always compare the lever arms (input vs output) to find mechanical advantage.

Answer 1

Correct Answer: 400

Step 1: Identify lever arms.
- The pliers act like two levers pivoted at the joint. - Input force = \(P = 100 \, N\). - Distance from pivot to input force = 100 mm. - Distance from pivot to output jaw = 25 mm.

Step 2: Apply principle of moments.
For equilibrium: \[ \text{Input moment} = \text{Output moment} \] \[ P \times L_{in} = F_{jaw} \times L_{out} \]

Step 3: Substitute values.
\[ 100 \times 100 = F_{jaw} \times 25 \] \[ F_{jaw} = \frac{100 \times 100}{25} = 400 \, N \]

Step 4: Interpretation.
- Each jaw exerts a force of 400 N on the workpiece. - The mechanical advantage = \(\dfrac{L_{in}}{L_{out}} = \dfrac{100}{25} = 4\). Final Answer:
\[ \boxed{400 \, N} \]