Physics estimations

[asum O_o]

Hello!
can you please provide me with all the estimations that have been asked in physics paper 2.
like volume of adult person's head, mass of protectors an stuffs like that. I would really be thankful to you! All the best for students appearing 9702/22 this Wednesday...

 

[N.M]

Hello!
can you please provide me with all the estimations that have been asked in physics paper 2.
like volume of adult person's head, mass of protectors an stuffs like that. I would really be thankful to you! All the best for students appearing 9702/22 this Wednesday...

AsSalamu alaikum wr wb...

here are a few of them that are commonly asked....


audible frequency of sound: 20Hz - 20 KHz

speed of sound in air : 300-330 m/s

time taken for sound to travel 1km in air;
T=1000/300
t= 3.33 sec

volume of an adult's head:
4/3pie(r^3)
take r from 6-9 cm
so acceptable values 900-6000 cm^3

mass of an adult: 80kg

diameter of a nucleus: 10^-15

diameter of an atom: 10^-10

time taken for an athlete to cover 100m: 10 sec

K.E of that same athlete: 1/2 mv^2
v=dist/time
100/10
v=10
0.5 x 80 x 10^2
K.E=4000J

wavelength of red light: 650nm

wavelength of violet light: 450nm

frequency: v=f (lambda)
v= 3 x 10^8
so calculate it for any given wavelength of light

density of water; 1g/cm^3
1kg/m^3

density of air: 1.3kg/m^3

weight of 1000cm^3 of water:
vol=1000cm^3
d= 1 g/cm^3
M=density*volume
M= 1000 g
m=1kg
W=mg
W= 1 x 10
W= 10N

mass of an apple: 200g or 250g

mass of a protractor; 30g

mass of a 30cm ruler: 50g

pressure due 10m depth of water:
P=pgh
(1000)(10)(10)
P=10^5 Pa

P.S: these are just rough estimates examiner accept a range of values

 

[CaptainDanger]

Some of the Reasonable Estimates

Speed of sound in air : 300-330 m/s

Speed of light or any electromagnetic wave : 3 x 10^8 m/s

Density of air at room temperature and pressure : 0.5 - 1.5 kg /m^3

Mass of a Protractor : 5-50 g

Volume of Head of a Person : 2 x 10^3 cm3 to 9 x 10^3cm3

Mean K.E of an athlete to run 100 m race : 4000 J

Suitable values of wave lengths for Electromagnetic Radiations : Learn those by heart.

Pressure due to depth of 10 m of water : 9.8 x 10^4 Pascals

Diameter of an atom : Order of 10^-10 m

 

[asum O_o]

Thank you so much friend! I really appreciate your help! Sorry for this late reply