Chapter 1 : answer

Paper 2

1a

Base Quantity	Symbol	Name of Unit	Symbols for unit
Length	l	meter	m
Mass	m	kilogram	kg
Time	t	second	s
Temperature	T	Kelvin	K
Electric current	I	Ampere	A

1b

Derived Quantity	Relation with base quantity	Symbol for derived quantity
Area	l 2	A
Volume	l 3	V
Density	m l -3	ρ
speed	l t -1	v
force	ml t -2	F

2a)  6.87 X 10⁴ kg  ;  3.26 x10 ^-6 s ; 5.62 x 10⁸ m  ; 4.02 x10² K  ; 5.2 x10 ^-7 A

b)  3.0 x 10⁴ m²   ;  4.5 x 10⁷ m³  ;  6.0 x 10 ^-2 kgm^-3  ;   3.0 x 10⁴ ms^-1   ;  9.0 x 10 ^-4 N

3b)  2.5 x 10⁷ m  ;   6.27 x10⁵ V  ;   2.45 x10 ^-3 s  ;   9.8 x10 ^-4 A   ;   2.0 x 10⁰ kg

3c)  4.6 x 10^-5 m²    ;    3.52 x10^-25 m³   ;   3.8 x 10⁷ m²

3d)  8.65x10⁸ kgm^-3   ;   2.083 x 10¹ ms^-1  ;  6.42 x10^-1 ms^-1  ;  2.0 x 10⁹ Nm^-2( wrong question )

3e)  7.0 x10^-3 W  ;  3.45 x 10¹⁴ V  ;   9.87 x10^-2 C  ;   1.48 x 10 ^-10 Js^-1  ;    1.23 x10 ^-2 As^-1

4a) thickness of paper  = 0.0008 m ;  length of pen = 0.062 m  ;  height of a girl = 1.6 m

      Radius of earth =  6.4 x10⁶ m   ;    length of a ruler = 0.5 m

4b) compact disc = micrometer screw gauge ;  ping pong ball = vernier calliper

Table  =  meter ruler  ;  volume = measuring tape    ; electric current = ammeter

5a) to avoid zero error      ii) to get actual reading

5b) 4.0 cm  ;  0.44 cm  ;  to get average reading & more accurate

5C) micrometer screw gauge ; accuracy up to 0.01 mm

6a) inside jaws ; measure the internal diameter of the tubes

6b) do repeating  measurement

6c) 1.55 cm ; 1 x 10 ⁷

7a) 28.3°C  ;   7b)  when the mass increase , the temperature also increase ; 7c) 10 kg°C

 7d)   1.82 kg   ;  7e)  32.5 °C

8a)  ratchet  ;  avoid  tightening the screw too much

8b) – 0.04 mm  ;   0.01 mm    8c)  2.89 mm

9a) no unit for time , no symbols for distance  ;  reading not  consistent

9c) 500/52.6  =  9.5 cms^-1

9d) ticker timer & ticker tape.

Section B and section C – will be discuss in the classroom