American Community School at Beirut
IB 1 Physics
Topic 1.1: Measurements in Physics
IB Questions
1.
Which one of the following units is a unit of energy?
A.
eV
B.
W s–1
C.
W m–1
D.
N m s–1
(1)
2.
The ratio
diameter of a nucleus
is approximately equal to
diameter of an atom
A.
10–15.
B.
10–8.
C.
10–5.
D.
10–2.
(1)
3.
The diameter of the nucleus of a hydrogen atom is of the order of
A.
10–8 m.
B.
10–15 m.
C.
10–23 m.
D.
10–30 m.
(1)
4.
The unit, the electron-volt is equivalent to
A.
1.6 × 1019 J.
B.
1.0 J.
C.
1.6 × 10–19 J.
D.
9.1 × 10–31 J.
(1)
1
5.
The number of heartbeats of a person at rest in one hour, to the nearest order of magnitude is
A.
101.
B.
102.
C.
103.
D.
105.
(1)
6.
The diameter of a proton is of the order of magnitude of
A.
10–12 m.
B.
10–15 m.
C.
10–18 m.
D.
10–21 m.
(1)
7.
Which one of the following is a fundamental unit?
A.
Coulomb
B.
Ohm
C.
Volt
D.
Ampere
(1)
8.
The resistive force F acting on a sphere of radius r moving at speed v through a liquid is given
by
F = cvr
where c is a constant. Which of the following is a correct unit for c?
A.
N
B.
N s–1
C.
N m2 s–1
D.
N m–2 s
(1)
2
9.
The order of magnitude of the weight of an apple is
A.
10–4 N.
B.
10–2 N.
C.
1 N.
D.
102 N.
(1)
10.
Which one of the following contains three fundamental units?
A.
Metre
Kilogram
Coulomb
B.
Second
Ampere
Newton
C.
Kilogram
Ampere
Kelvin
D.
Kelvin
Coulomb
Second
(1)
11.
The ratio
diameter of hydrogen atom
to the nearest order of magnitude is
diameter of hydrogen nucleus
A.
102.
B.
105.
C.
1010.
D.
1015.
(1)
2.
The kWh is equal to
A.
1.0 × 103 J.
B.
3.6 × 103 J.
C.
6.0 × 104 J.
D.
3.6 × 106 J.
(1)
3
13.
The mass of an atom of the isotope strontium-92 (92Sr) is of the order of
A.
10–23 kg.
B.
10–25 kg.
C.
10–27 kg.
D.
10–29 kg.
(1)
14.
The mass of an electron is 9.1  10–31 kg and that of a proton is 1.7  10–27 kg. Which one of
the following is the difference in the order of magnitude of the masses of the electron and the
proton?
A.
10.8
B.
7.4
C.
5.4
D.
3
(1)
15.
Sub-multiples of units may be expressed using a prefix. Which one of the following lists the
prefixes in decreasing order of magnitude?
A.
centi-
micro-
milli-
nano-
B.
milli-
centi-
nano-
micro-
C.
centi-
milli-
micro-
nano-
D.
milli-
micro-
centi-
nano(1)
16.
The volume of the Earth is approximately 1012 km3 and the volume of a grain of sand is
approximately 1 mm3. The order of magnitude of the number of grains of sand that can fit in the
volume of the Earth is
A.
1012.
B.
1018.
C.
1024.
D.
1030.
(1)
4
17.
The time interval between human heartbeats is of the order of
A.
10–2 s.
B.
10–1 s.
C.
100 s.
D.
101 s.
(1)
18.
The length of a page of the examination paper is approximately 30 cm.
Which of the following gives the order of magnitude for the time taken for light to travel the
length of the page?
A.
10–7 s
B.
10–8 s
C.
10–9 s
D.
10–10 s
(1)
19.
Which of the following contains only fundamental SI units?
A.
ampere
newton
second
B.
volt
second
kelvin
C.
mole
ampere
kilogram
D.
kilogram
metre
tesla
(1)
20.
The molar mass of water is 18 g. The approximate number of water molecules in a glass of
water is
A.
1022.
B.
1025.
C.
1028.
D.
1031.
(1)
5
21.
Which list gives the masses of the particles in ascending order of magnitude?
least → greatest
A.
α-particle
β-particle
proton
B.
proton
α-particle
β-particle
C.
proton
β-particle
α-particle
D.
β-particle
proton
α-particle
(1)
22.
The resistive force F that acts on an object moving at speed v in a stationary fluid of constant
density is given by the expression
F = kv2
where k is a constant.
(a)
State the derived units of
(i)
force F.
...........................................................................................................................
(1)
(ii)
speed v.
...........................................................................................................................
(1)
(b)
Use your answers in (a) to determine the derived units of k.
.....................................................................................................................................
.....................................................................................................................................
(1)
(Total 3 marks)
23.
This question is about units and momentum.
(a)
Distinguish between fundamental units and derived units.
.....................................................................................................................................
.....................................................................................................................................
(1)
6
(b)
The rate of change of momentum R of an object moving at speed v in a stationary fluid of
constant density is given by the expression
R = kv2
where k is a constant.
(i)
State the derived units of speed v.
...........................................................................................................................
(1)
(ii)
Determine the derived units of R. ( the formula for momentum is m.v where m is
the mass of the object and v is its velocity).
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
(2)
(iii)
Use the expression and your answers in (b)(i) and (b)(ii) to determine the derived
units of k.
...........................................................................................................................
...........................................................................................................................
(1)
7