physics

1 which expression has the same si base units as pressure?
a force
length x speed
b force.
length x time
c mass
length x (time)
p mass x (time)?
length

2 what is an approximate value for the speed of sound in air?
a 30ms" b 300ms" c 30000ms' d 300000000ms"

3 a pendulum bob is held stationary by a horizontal force h. the three forces acting on the bob are
shown in the diagram.
30°
t
h
w
the tension in the string of the pendulum is t. the weight of the pendulum bob is w. the string is
held at an angle of 30° to the vertical.
which statement is correct?
a h=tcos30
b t=hsin30
c w=tsin30
d w=tcos30

4 a sstudent is investigating an electrical signal using a cathode-ray oscilloscope (c.r.0).
the frequency of the signal is 50 khz.
which time-base setting on the oscilloscope should be used?
a 50mscm* b 1mscm' c 10uscm"' d 0.5uscm"'

2» a student wisnes to measure a distance of about 10cm to a precision of 0.01 cm.
which measuring instrument should be used?
a metre rule
b_ micrometer
c tape measure
d vernier calipers
eee t= eet

6 an aircraft, initially stationary on a runway, takes off with a speed of 85kmh™ in a distance of no
more than 1.20km.
what is the minimum constant acceleration necessary for the aircraft?
a 0.23ms? b 0.46ms? c 3.0ms? d 60ms?

8 the acceleration of free fall on pluto is 0.66ms ~.
an object weighs 6.0 n on earth.
what would this object weigh on pluto?
a 0.40n b 0.93n c 4.0n d 39n

9 water flows out of a pipe and hits a wall.
wall
pipe velocity v
——_—>
sss cross-sectional
_—— area a
water
when the jet of water hits the wall, it has horizontal velocity v and cross-sectional area a.
the density of the water is ». the water does not rebound from the wall.
what is the force exerted on the wall by the water?
2
pv py 7
a — b ah cc "av d av
a a pi pi

10 a stationary firework explodes into three pieces. the masses and the velocities of the three
pieces immediately after the explosion are shown.
v4 vo
50g 50g
60° 60°
100g
8ms"
what are speed v; and speed v2?
[ns [ats |
a 4.0 4.0
b 9.2 9.2
cc 14 14
d 16 16

11 aspherical object falls through water at constant speed. three forces act on the object.
which diagram, showing these three forces to scale, is correct?
a b cc d

12 a uniform metre rule of weight 2.0n is pivoted at the 60cm mark. a 4.0n load is suspended from
one end, causing the rule to rotate about the pivot.
uniform metre rule we
pivot | oa (/
4
k-—7 load
=e
sf
4.0n
at the instant when the rule is horizontal, what is the resultant moment about the pivot?
a 0.0nm b 1.4nm cc 1.6nm d 1.8nm

13 the vertical forces that the ground exerts on a stationary van are shown.
16000n 9000 n
xc_|
fo :
tan zn |
yd om
0.600m 1.500m 0.400m
the van is 2.50m long with the wheels at a distance of 0.600m from the front of the van and
0.400 m from the rear of the van.
what is the horizontal distance of the van’s centre of gravity from the front of the van?
a 0.540m b 0.960m cc 1.14m d = 1.36m

14 an object hangs by means of two cords around two rods, as shown.
rod & c) rod
tl ] lc]
f i f,
object > q
the object is held in equilibrium by the forces f, and fy. the object weighs 10n. there is
negligible friction between the rods and cords. angle 0 is 90°.
which row of the table gives an angle 6 of 90°?
fon [aw
a 4.0 6.0
b 6.0 4.0
cc 6.0 8.0
d 8.0 6.0

15 which force is caused only by a pressure difference?
a friction
b upthrust
c viscous force
d~ weight

16 the total energy input e, in a process is partly transferred to useful energy output u and partly

transfered to energy that is wasted w.

what is the efficiency of the process?

a z* 100%

b a 100%

cc as 100%

p y+w, 100%

ba

17 agas is enclosed inside a cylinder which is fitted with a frictionless piston.
v, piston
—-—$___—o —_
y a
pit
a
gas _—————
pil
<= 1 1
oo
v,
initially, the gas has a volume v;, and is in equilibrium with the external pressure p. the gas is
then heated slowly so that it expands at constant pressure, pushing the piston back until the
volume of the gas has increased to v3.
how much work is done by the gas during this expansion?
a p(ve-vi) bd p(ve- vi) © p(vot vs) = ds p(va + v4)

18 a projectile is thrown at an angle to the ground.
23.0ms"
projectile path
10.1ms
ground

at a certain time, the projectile has a horizontal velocity of 23.0ms™' and a vertical velocity

of -10.1ms™.

what is the speed of the projectile at this time?

a 12.9ms" b 20.7ms™ c 25.1ms" d 33.1ms™

19 acar of mass 1400kg is travelling on a straight, horizontal road at a constant speed of 25ms™.
the output power from the car’s engine is 30kw.
the car then travels up a slope at 2° to the horizontal, maintaining the same constant speed.
25ms"
1400kg a=
o—=© —— 3°
what is the output power of the car’s engine when travelling up the slope?
a 12kw b 31kw cc 42kw d 65kw

20 two wires x and y are made of different metals. the young modulus of wire x is twice that of
wire y. the diameter of wire x is half that of wire y.
the wires are extended with the same strain and obey hooke’s law.
what is the ratio tension in wire x 9
tension in wire y
a 1 b 1 c 1 d 8
8 2

21 a weight of 120kn is placed on top of a metal column. the length of the column is compressed
by 0.25mm. the column obeys hooke’s law when compressed.
how much energy is stored in the compressed column?
a 15j b 30j c 15kj d 30kj

22 what is the relationship between the amplitude of a wave and its intensity?
a amplitude « intensity
b amplitude « (intensity)’
c amplitude « intensity
d (amplitude)* « ./intensity

23 which statement about light waves and sound waves is correct?
a both light waves and sound waves show the doppler effect.
b light waves can be diffracted but sound waves cannot be diffracted.
c_ sound waves are transverse waves and light waves are longitudinal waves.
d sound waves can travel in a vacuum but light waves cannot travel in a vacuum.

24 the diagram shows two waves r and s.
displacement
wave r
0
| wave s__ time
wave r has an amplitude of 8cm and a period of 30ms.
what are the amplitude and the period of wave s?
a 2 10
b 2 90
cc 4 10
d 4 90

25 a source of sound waves is travelling as shown.
in which situation would the stationary observer detect the largest decrease in the observed
frequency?
a b
observer source observer source
e e e e
+ 5ms" + 10ms"*
cc d
observer source observer source
e e e e
—— > 5ms" ——> 10ms"

26 mand n are two electromagnetic waves.
the ratio
wavelength of m _ 10°.
wavelength of n
what could m and n be?
ee eee ee
a microwaves visible light
b microwaves y-fays
cc y-rays microwaves
d visible light microwaves

27 a progressive wave is incident normally on a flat reflector. the reflected wave overlaps with the
incident wave and a stationary wave is formed.
at an antinode, what could be the ratio srree eet hee at any instant?
displacement of the reflected wave
a -1 bo cc 1 d 2

28 a monochromatic plane wave of speed c and wavelength j is diffracted at a small aperture.

the diagram illustrates successive wavefronts.
g
)
h |

after what time will some portion of the wavefront gh reach point p?

a 34 b 24 c 34 p 44

2c c ie) é

29 in an experiment to demonstrate two-source interference of light, a beam of light is split into two
beams using two slits 0.50mm apart. these two beams are incident on a laboratory wall at a
distance of 4.0m.

the wavelength of light is 550nm.
how far apart are two adjacent interference fringes that are formed on the laboratory wall?
a 0.22mm b 0.44mm cc 2.2mm d 4.4mm

30 two positive charges and one negative charge, all of equal magnitude, are set at the corners of
an equilateral triangle.
which diagram best represents the electric field surrounding the charges?
a b
cc d

31 a constant potential difference is applied between two horizontal metal plates. a charged oil
droplet is held stationary by the electric field between the plates.
|
charged / metal plates
oil drop,
as some of the oil evaporates, the droplet loses mass and starts to accelerate. its charge
remains constant.
in which direction does the droplet accelerate, and which change needs to be made to the
separation of the plates in order to stop this acceleration?
direction of separation
acceleration of the plates
a downwards decrease
b downwards increase
cc upwards decrease
d upwards increase

32 an electric current j is given in the list of formulae on page 3 as i = anvq.
what do each of the symbols represent for an electric current in a metal wire?
i
a area of number of free voltage charge of
cross-section electrons each molecule
b area of number of free average charge of
cross-section electrons per drift speed each electron
unit volume of electrons
cc current number of free average charge of
electrons drift speed each molecule
of electrons
d current number of free voltage charge of
electrons per each electron
unit volume

33 the potential difference across a resistor is 12. the current in the resistor is 2.0a.
a charge of 4.0c passes through the resistor.
what is the energy transferred in the resistor and the time taken for the charge to pass through
the resistor?
[ees [ners
a 3.0 2.0
b 3.0 8.0
cc 48 2.0
d 48 8.0

34 a coil contains n turns of insulated copper wire wound on to a cylindrical iron core of diameter d.
the copper wire has a diameter d. the resistivity of copper is . diameter d is much greater than
diameter d.

what is the total resistance between the two ends of the coil?
a 4ned b 4nod cc 8npd d 8nod
d? d? ad? d?

39 =|wo cells are connected to a load resistor of resistance 3.00. ihe electromotive force (e.m.1).
and the internal resistance of each of the cells is shown.
'60v | i30v
: 0.82: | 1.2q :
3.0q
what is the current in the load resistor?
a 0.60a b 1.2a c 1.8a d 3.0a

36 six resistors, each of resistance r, are connected as shown.
the combined resistance is 66 kq.
what is the value of r?
a 11kq b 18kq c 22kq d 36kq

37 a potential divider consists of two resistors of resistances r, and r, connected in series across a
source of potential difference (p.d.) vin. the p.d. across rj is vout.
oo
| in
vin °
ik ~
o o
which changes to r, and to r; will increase the value of vout?
ee ee
a doubled doubled
b doubled halved
cc halved doubled
d halved halved

38 which row describes the relative ionizing power and the relative penetration power per unit length

in air of a-particles and y-rays?

[ereries |e
a least ionizing least penetrating
b least penetrating most ionizing
c most ionizing most penetrating
d most penetrating least ionizing

ee

39 a nucleus of sodium-21, {,na, decays to form a new nucleus containing 10 protons
and 11 neutrons.
which leptons are emitted from the sodium-21 nucleus during the decay?
a apositron and an antineutrino
b= apositron and a neutrino
c_ anelectron and an antineutrino
d_anelectron and a neutrino

40 a neutron decays to form a proton.
which particle is not involved in the decay process?
a _antineutrino
b down quark
c positron
d up quark

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