Final answer:
The force applied when holding a pencil is generally small but can lead to stress and strain on the pencil's materials during use. Situations like using an eraser or tapping the lead require consideration of material properties and static friction to calculate the effects of applied force.
Step-by-step explanation:
The force applied when holding a pencil can be analyzed within the domain of Physics, specifically looking into the mechanics of statics and dynamics. The amount of force is relatively minimal, typically under 1 Newton (N), as it is only the force required to counteract the weight of the pencil and enable the user to manipulate it. However, more substantial forces are involved when actions such as writing, erasing, or tapping the pencil lead are considered. These forces can cause stress and strain in the material of the pencil and are governed by Hooke's Law and the material properties described by Young's Modulus.
Examples and Calculations
For instance, when using a pencil eraser, exerting a vertical force of 6.00 N at a distance of 2.00 cm from the hardwood-eraser joint induces a specific amount of flex and compression in the pencil's wood, depending on its mechanical properties such as Young's Modulus.
In the case of the pencil lead, a force of 4.0 N applied along the axis causes a change in length governed by the lead's Young's Modulus of about 1 × 10⁹ N/m². Considering a lead that is 0.50 mm in diameter and 60 mm long, we would calculate the change in length to determine the material's response to the force. An understanding of static friction is also invaluable when considering situations like a pencil resting at an angle against a surface, where the force of friction in relation to the pencil's weight and the angle of contact determines whether the pencil will slip or remain in place.