AP Physics C: Mechanics Flashcards: Rolling

Question 1

How is the total kinetic energy of an object that is both translating and rotating calculated?

Accepted Answer

The total kinetic energy is the sum of the system’s translational kinetic energy and its rotational kinetic energy.

Question 2

Why does a rolling object have more kinetic energy than a non-rotating object of the same mass moving at the same translational speed?

Accepted Answer

A rolling object possesses both translational and rotational kinetic energy, while a non-rotating (sliding) object only has translational kinetic energy.

Question 3

For an object rolling without slipping, what equation connects the center of mass acceleration ($a_{cm}$) to its angular acceleration ($\alpha$)?

Accepted Answer

The center of mass acceleration is related to the angular acceleration by the equation $a_{cm}=r\alpha$.

Question 4

What does it mean for an object to be "rolling without slipping"?

Accepted Answer

Rolling without slipping means the translational motion of the object's center of mass is directly related to its rotational motion, such that the point of contact with the surface is momentarily at rest.

Question 5

What two distinct types of motion are combined to describe the overall motion of a rolling object?

Accepted Answer

The motion of a rolling object is a combination of the translational motion of its center of mass and the rotational motion about its center of mass.

Question 6

What is the equation for the total kinetic energy ($K_{tot}$) of a rolling object?

Accepted Answer

The equation for total kinetic energy is $K_{tot}=K_{trans}+K_{rot}$.

Question 7

For an object rolling without slipping, how is the displacement of the center of mass ($\Delta x_{cm}$) related to its angular displacement ($\Delta	heta$)?

Accepted Answer

The relationship is given by the equation $\Delta x_{cm}=r\Delta	heta$, where r is the radius.

Question 8

In an ideal case of rolling without slipping, what is the role of the frictional force regarding energy?

Accepted Answer

In ideal cases, the frictional force for an object rolling without slipping does not dissipate any energy from the system.

Question 9

For an object rolling without slipping, what equation relates the center of mass velocity ($v_{cm}$) to its angular velocity ($\omega$)?

Accepted Answer

The relationship is given by the equation $v_{cm}=r\omega$, where r is the radius of the object.

Question 10

A ball with a radius of 0.1 m rolls without slipping. If its center of mass accelerates at 2 m/s², what is its angular acceleration ($\alpha$)?

Accepted Answer

Using the equation $a_{cm}=r\alpha$, the angular acceleration is $\alpha = a_{cm}/r = (2 	ext{ m/s²}) / (0.1 	ext{ m}) = 20 	ext{ rad/s²}$.

AP Physics C: Mechanics Flashcards: Rolling

All Flashcards (10)