What type of friction is defined as the amount of force required to start a body in motion?

The correct answer is static friction, which is the force that must be overcome to initiate motion between two surfaces that are in contact but not moving relative to each other. When an object is at rest, static friction acts to keep it stationary. It is generally greater than the other types of friction because it must counteract the initial inertia of the object and any other forces acting on it, such as gravity on a slope or friction from other surfaces.

This type of friction is important in various applications, such as ensuring that a vehicle does not slip when starting from a stop or allowing an object to be pushed without it sliding immediately. Static friction varies based on the materials in contact and the normal force pressing them together, which is why understanding it is crucial for applications involving movement and stability.

The other types of friction mentioned are related but apply to different scenarios. Dynamic friction, also referred to as kinetic friction, occurs when two surfaces are sliding against each other. Kinetic friction is usually lower than static friction. Rolling friction pertains to the forces resisting the motion when an object rolls, such as a wheel. Each of these types has distinct characteristics and applications, but static friction is specifically defined as the force required to initiate motion, making it the correct answer in this