Chapter 2: Rotational Dynamics Practice Flashcards

A set of fill-in-the-blank practice flashcards covering Grade 11 Physics Chapter 2: Rotational Dynamics, including vector products, torque, moment of inertia, and conservation of angular momentum.

The dynamics of rotational motion involves describing the __________ of an object in terms of its rotational inertia and the torques that act on it.

angular acceleration

The scalar product of vectors $A$ and $B$ is defined by the formula $A \cdot B = \_\_\_\_\_\_\_\_\_\_$.

$$AB \cos(\theta)$$

Although force and displacement are vectors, _________ is a scalar product of the two.

work

The vector product between two vectors is denoted by a cross (x) and is also called the _________.

cross product

The magnitude calculation for the vector product $C = A \times B$ is $C = \_\_\_\_\_\_\_\_\_\_$.

$$AB \sin(\theta)$$

Unlike the scalar product, the vector product does not obey the _________ property.

commutative

According to the _________, your thumb will point in the direction of the cross product $A \times B$ if your index finger points to $A$ and your middle finger points to $B$.

right-hand rule

The turning effect of a force about a particular fulcrum is measured by the _________ or torque.

moment of force

The vector form of torque is expressed as $\tau = \_\_\_\_\_\_\_\_\_\_$.

$$\vec{r} \times \vec{F}$$

In SI units, the moment of force (or) torque is measured in _________.

$$\text{N\,m}$$

The perpendicular distance from the line of action of the force to the fulcrum ($d = r \sin(\theta)$) is called the _________ of a force.

moment arm

The relation between torque and angular acceleration is given by $\tau = \_\_\_\_\_\_\_\_\_\_$.

$$I \alpha$$

The SI unit for the moment of inertia is _________.

$$\text{kg\,m}^2$$

The moment of inertia for a hoop or cylindrical shell is given by the formula $I = \_\_\_\_\_\_\_\_\_\_$.

$$MR^2$$

The moment of inertia for a solid sphere about its axis of rotation is $I = \_\_\_\_\_\_\_\_\_\_$.

$$\frac{2}{5} MR^2$$

For a long thin rod with the rotation axis through its center, the moment of inertia is $I = \_\_\_\_\_\_\_\_\_\_$.

$$\frac{1}{12} ML^2$$

Static equilibrium occurs when both the resultant force and the _________ on the system are zero.

resultant torque

The _________ states that if an object is to be in balance, the total clockwise moment about the fulcrum must equal the total anticlockwise moment.

principle of moments

The _________ of a particular object is a point at which all its weight may be considered to act.

centre of gravity

In rotational motion, angular momentum is defined as the product of moment of inertia and _________.

angular velocity

The SI unit of angular momentum ($L$) is _________.

$$\text{kg\,m}^2\,s^{-1}$$

The _________ states that if there is no net external torque acting on an isolated system, the total angular momentum remains constant.

law of conservation of angular momentum

For an ice skater, the rate of spin increases as the moment of inertia decreases because she pulls her _________.

arms inwards