Question

Select all that apply.

The resistance to an object being pulled over a surface is called _____.

starting friction
sliding friction
static friction
kinetic friction

Answer 1

The resistance to an object being pulled over a surface is called static friction before movement and kinetic friction once the object is in motion. Static friction must be overcome to start an object moving, whereas kinetic friction is what resists an object's motion once it is sliding.

Step-by-step explanation:

The resistance to an object being pulled over a surface is called static friction before the object starts moving and kinetic friction once the object is in motion. Static friction is the force that must be overcome to start moving an object at rest. It increases to be equal to and in the opposite direction of the applied force. Once an object starts to move, static friction transitions to kinetic friction, which is usually less than static friction and acts between objects that are moving relative to each other.

For example, pushing a heavy crate across the floor involves overcoming static friction first. Once the crate begins to slide, kinetic friction takes over and is the force that must be overcome to keep the crate moving. Kinetic friction tends to be lower than static friction, making it easier to keep an object in motion than to start moving it from rest. Altering the mass of the object or the surface properties, such as adding oil, can change the amount of force needed either to overcome static friction or to continue overcoming kinetic friction.

Answer 2

Answer: The correct answer are sliding friction and kinetic friction.

Step-by-step explanation:

Friction opposes the motion of the objects. It is always directed to an opposite direction of the motion of the object.

Kinetic friction: This friction occurs when the two objects are moving relative to each other. Kinetic friction is also dynamic friction or sliding friction.

Sliding friction: When the object slides then the friction comes into the play is called sliding friction.

Static friction: When the object is not on the verge of the motion then the friction is called static friction. Here, the friction is more than the applied force. This friction occurs when the two objects are not moving relative to each other.

Therefore, the resistance to an object being pulled over a surface is called kinetic friction or sliding friction.