Rotational Motion

Question 1

is defined as the tendency of an object at rest to remain at rest
and an object in motion to stay moving in a straight line at a constant velocity.

Answer 1

Inertia

Question 2

also known as rotational inertia

Answer 2

Moment of Inertia

Question 3

defined as the property of a rotating body to resist change in its state of rotation.

Answer 3

Moment of Inertia

Question 4

SI unit for Moment of Inertia

Answer 4

kg ⋅m²

Question 5

True or False:
Moment of inertia depends on the
distribution of the mass.

Answer 5

TRUE

Question 6

True or False:
A mass which is at
greater distance from the axis of rotation has a
greater moment of inertia compared to the
same mass which is near the axis of rotation.

Answer 6

TRUE

Question 7

gives a measurement of the resistance of the body
to a change in its rotational motion.

Answer 7

Moment of Inertia

Question 8

The moment of inertia of a particle about an axis is obtained by multiplying the mass by the square of its distance from the axis.

Answer 8

I = mr², where m is mass, and r is the distance from the axis of rotation.

Question 9

is the distance from an axis of rotation where the mass of a body may be assumed to be concentrated without altering the
moment of inertia of the body about that axis

Answer 9

Radius of gyration (𝑘)

Question 10

The effectiveness of a force in rotating a body on which it acts is called

Answer 10

Torque 𝑟

Question 11

can be determined by multiplying the force applied F by the perpendicular distance from the axis of rotation to the line
along which the force acts.

Answer 11

Torque

Question 12

This perpendicular distance is called

Answer 12

Moment Arm or lever arm

Question 13

Torque Formula

Answer 13

𝑟 = Frsin(theta)

Question 14

If theta is = 90 can use the formula

Answer 14

𝑟 = 𝐹r

Question 15

Torque Quantity

Answer 15

m⋅N or m⋅ (kg⋅m/s²)

Question 16

True or False:
By convention, torque
is positive if it tends to produce counterclockwise rotation. It is negative if it tends
to produce clockwise rotation.

Answer 16

TRUE

Question 16

The greater the torque applied to an object, the greater its tendency to rotate

Answer 16

TRUE

Question 17

refers to the motion of a body turning about an axis, where each
particle of the body moves along a circular path.

Answer 17

Rotation

Question 18

The angular position is represented by

Answer 18

Theta

Question 19

The units for angular displacement may be

Answer 19

Degree, Radians, Revolution
(1 revolution = 360° = 6.28 radians = 2 π radians)

Question 20

is the rate at which angular displacement changes
with time.

Answer 20

Angular Velocity (ω)
may be expressed in deg/s, rad/s, or rev/s

Question 21

is the time rate of change of angular velocity.

Answer 21

Angular Acceleration � (Alpha)
maybe expressed in deg/s2, rad/s2, or rev/s2

Question 22

is concerned with the calculation of forces acting on and within
structures that are in equilibrium.

Answer 22

Statics

Question 23

is defined as a body at rest having zero acceleration and zero net force.

Answer 23

Static Equilibrium

Question 23

is defined as a body at rest having zero acceleration and zero net force.

Answer 23

Static Equilibrium

Question 24

is a useful concept when dealing with equilibrium problem

Answer 24

Center of Mass/Gravity

Question 25

is the point where its entire weight may be assumed to be concentrated.

Answer 25

Center of Gravity of a Body

Question 26

the resultant of the forces acting on a body is not zero, the addition of another force called the ___________ is needed to balance the resultant to produce translational equilibrium.

Answer 26

Equilibrant

Question 26

The center of gravity of regularly shaped (symmetrical) objects is located at their geometric centers. However, some objects have their centers of gravity located toward their thicker (massive) end and some objects located outside them

Answer 26

TRUE

Question 27

2 conditions of body to be in rotational equilibrium.

Answer 27

The vector sum of all forces acting on it must be zero. (Translational) The sum of all torques about any point must be zero. (Rotational)

Question 28

is that which something moves through space but doesn’t rotate.

Answer 28

Translational Motion

Question 29

description of motion.

Answer 29

Kinematics

Question 29

description of motion.

Answer 29

Kinematics

Question 29

linear speed of a point on the rim

Answer 29

tangential speed

Question 30

is the angle swept out by any line passing through a rotating body that intersects the axis of rotation.

Answer 30

Angular displacement (θ), value is positive if going counter-clockwise, negative if going clockwise

Question 31

is derivative of the change of angular displacement over a change of time. Counterclockwise rotation is positive angular velocity and negative if clockwise.

Answer 31

Angular Velocity

Question 32

rotational analogue for rotational motion

Answer 32

Angular Momentum (L), kg∙m2/s.