(a) It is a non-uniform motion
(b) 20 cm
(c) Velocity = \(\frac { Displacement }{ time\ taken } \)
=\(\frac { Total\ distance }{ time\ taken } \)
=\(\frac { 20\times 10^{ -2 } }{ 2.5 } \)
= \(\frac { 2 }{ 2.5 } \) = 0.08 m/s (or) cm/s.

(i) Speed = \(\frac { Distance }{ Time } \)= Distance = 1 km = 1000 m
Time =100 s
Speed = \(\frac { 1000 }{ 100 } \) =10 m/s
(ii) \(\frac { Displacement }{ time } \) = Velocity
Displacement = 1 km = 1000 m
Time = 100 s
Velocity = \(\frac { 1000 }{ 100 } \) = 10 m/s.

A separator is a high speed spinner. It acts on the same principle of centrifuge machines. The bowl spins at very high speed causing the heavier contents of milk to move outward in the bowl pushing the lighter contents inward towards the spinning axis. Cream is lighter than other components in milk. Therefore, skimmed milk which is denser than cream is collected at outer wall of the bowl. The lighter part of cream is pushed towards the centre from where it is collected through pipe.

The motorcycle has an acceleration of 4m/s², the velocity is increasing at the rate of 4 metre per second.

One can determine the distance moved by the car from its velocity - time graph. The area under the velocity - time graph gives the distance (magnitude of displacement) moved by the car in a given interval of time. Since the magnitude of the velocity of the car is changing due to acceleration, the distance S travelled by the car will be given by the area ABCDE under the velocity - time graph.

Speed: It is the rate of change of distance;
Average speed: It is defined as the total distance travelled, divided by the total time taken.

When the car turns around circle, it experiences centripetal acceleration
\(a=\frac { { v }^{ 2 } }{ r } \)
The solution is as follows \(=\frac { \left( 10 \right) ^{ 2 } }{ 25 } \)
\(=\frac { 100 }{ 25 } \)
a = 4 m s^‒2
To determine the net force acting upon the car, use the equation F = ma.
F = ma F = 900 × 4 F = 3600 N

\(speed=\frac { Distance\quad }{ Time } \)
Distance = speed × time = 346 × 5 = 1730m
Thus, the distance of location of lightning = 1730m