Question

Physics students study a piano being pulled across a room on a rug. They know that when it is at rest, it experiences a gravitational force of 2200 N. When it is being pulled with 1200 N it is sliding across the room in equilibrium, but the students feel like they had to pull harder than 1200 N at first to begin motion. Which best describes the friction acting on the piano? The static and kinetic frictional forces are equal, so the static frictional force is equal to 1200 N. The kinetic frictional force is greater than the static frictional force, so the kinetic frictional force is greater than 1200 N. The static frictional force is greater than the kinetic frictional force, so the static frictional force is greater than 1200 N. The static and kinetic friction are both equal to the gravitational force of 2200 N.

Answer 1

Answer:

The static frictional force is greater than the kinetic frictional force, so the static frictional force is greater than 1200 N.

Explanation:

The Frictional force is a force that acts against the motion of any object that moves on a surface, which is due to the interaction between the molecules on the object's surface and the surface molecules on which the object moves.

$\mu_k < \mu_s,$

As we know that by the above equation, Static friction is often stronger than kinetic friction (this is why making an object begin moving is usually harder than maintaining it in motion across a surface).

Therefore the option 3 is correct according to the given situation