Michigan Test for Teacher Certification (MTTC) Secondary Integrated Science Practice test

Which type of forces includes both push and pull interactions?

1. Inertia forces

2. Contact forces

3. Gravitational forces

4. Electromagnetic forces

The correct answer is: Contact forces

The choice of contact forces is appropriate because contact forces refer to the interactions that occur between objects that are in physical contact with each other. These forces encompass both push and pull actions. For instance, when you push a door open, you are exerting a force that directly contacts the door; similarly, when pulling a drawer, a force is applied that is also in direct contact. In contrast, inertia forces relate to an object’s resistance to changes in its state of motion, arising not from contact between objects but from their mass. Gravitational forces are a type of non-contact force that acts at a distance due to the mass of objects, specifically the attraction between them. Electromagnetic forces, also non-contact in nature, involve forces that arise from charged particles and include both attraction and repulsion but are characterized by their electromagnetic origin rather than direct physical contact. Thus, contact forces uniquely highlight the concept of interactions requiring direct engagement, effectively capturing both push and pull dynamics.