Question The picture shows a physics lab set up. 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 kinetic friction kinetic friction equilibrium equilibrium static friction static friction inertia
The correct response is inertia
When the index card is quickly pulled away from the glass in a horizontal direction, the disc falls straight down into the glass due to the concept of inertia. Inertia is the tendency of an object to resist changes in its motion. In this case, when the index card is removed, the disc continues to remain at rest, due to its inertia, until an external force acts on it.
The force of gravity pulls the disc downward, causing it to fall straight down into the glass. The disc's inertia keeps it in its initial position until the force of gravity overcomes this inertia and pulls it downward.
Therefore, the correct answer is inertia.
To understand why the disc falls straight down into the glass when the index card is quickly pulled away horizontally, we need to consider the forces acting on the disc and the concepts of friction and inertia.
First, let's analyze the forces involved. When the index card is in contact with the glass, there is friction between the two surfaces. This friction force opposes the motion between the card and the glass. Additionally, the force of gravity is acting downward, pulling the disc towards the Earth.
Now, let's consider the concept of kinetic friction. Kinetic friction occurs between two surfaces that are sliding past each other. In this situation, when the index card is pulled horizontally away from the glass, the friction force between the card and the glass acts in the opposite direction, resisting the motion. However, the frictional force is not sufficient to prevent the disc from falling.
On the other hand, we can exclude static friction from being the cause of the disc falling straight down in this scenario. Static friction occurs when two surfaces are at rest relative to each other and one attempts to initiate motion. In this case, when the index card is suddenly pulled, the force required to overcome static friction can momentarily cause the disc to remain in place. However, once the friction is overcome due to the sudden pull, the disc is then only affected by the force of gravity.
Finally, the key principle at play here is inertia. Inertia is the tendency of an object to resist changes in its motion. When the index card is pulled quickly, it imparts a horizontal force on the disc. However, the disc tends to stay at rest in its current vertical position due to its inertia. As a result, the disc falls straight down into the glass, rather than being pushed horizontally along with the card.
In summary, the disc falls straight down into the glass when the index card is quickly pulled away from the glass in a horizontal direction because of the combination of the forces of gravity and kinetic friction, as well as the inertia of the disc.