a picture shows an index card on top of a cup with a metal disk on top of the metal disk

Question

Why does the disc fall straight down into the glass when we quickly pull the index card away from the glass in a horizontal direction?

(1 point)
Responses

static friction
static friction

inertia
inertia

kinetic friction
kinetic friction

equilibrium

Answer 1

The reason the disc falls straight down into the glass when you quickly pull the index card away is due to inertia. Inertia is the tendency of an object to resist changes in its state of motion. When the index card is pulled away quickly, the disc does not have enough time to adjust to the change, so it continues moving vertically downward due to gravity while the card is removed. Therefore, the correct response is:

inertia.