2. Mechanics

Question 1

rotational equilibrium definition (2)

Answer 1

A system is said to be in rotational equilibrium when resultant force and resultant torque acting are both zero + The sum of the clockwise moments is equal to the sum of the anticlockwise moments

Question 2

The moment of inertia of a rigid, extended body is defined as:

Answer 2

The resistance to a change of rotational motion, depending on the distribution of mass around a chosen axis of rotation

Question 3

Angular displacement is defined as:

Answer 3

he change in angle through which a rigid body has rotated relative to a fixed point

Question 4

reference frame

Answer 4

A set of coordinates to record the position and time of events`

Question 5

inertial reference frame (2)

Answer 5

A reference frame that is non-accelerating. Therefore, all inertial reference frames are moving at constant velocity with respect to each other

Question 6

Galilean Relativity

Answer 6

Galilean relativity states that Newton’s laws of motion are the same in all inertial reference frames

Question 7

First Postulate of special relativity

Answer 7

The laws of physics are the same in all inertial frames of reference (In our own reference frame, we are always stationary)

Question 8

Second Postulate of special relativity

Answer 8

The speed of light, c, in a vacuum, is the same in all inertial frames of reference +

Question 9

Proper time interval

Answer 9

The time interval between two events measured from within the reference frame in which the two events occur at the same place

Question 10

Proper length

Answer 10

The length measured in a reference frame where the object is at rest (relative to the observer)