PHYSICS FOR THE IB DIPLOMA: COURSEBOOK
Markscheme
1
a
The total momentum stays the same when no external forces act on
the system ✓
[2]
The carts exert equal and opposite forces on each other so the net
force is zero ✓
b
6.0 × 3.0 + 0 = (3.0 + 6.0) × v ⇒ v = 2.0 m s −1 ✓
[2]
Change in KE: __
1 × 3.0 × 6.0 2 − __
1 × 9.0 × (2.0) 2= 36 J✓
2
2
2
a
A very small percentage of the incident alpha particles were scattered
at very large scattering angles ✓
[2]
This required a huge electric force that could only be provided if the
positive charge of the atom was concentrated in a very small, massive
object ✓
b
I
[2]
92 U + 2 4 α
Pu → 235
239
94
Correct numbers for U✓
II
235 × 7.5909 + 4 × 7.0739 − 239 × 7.5603 ✓
[2]
5.25 MeV ✓
3
a
In a transverse wave the displacement is at right angles to the
direction of energy transfer ✓
[2]
In a longitudinal wave the displacement is parallel to the direction of
energy transfer ✓
b
I
λ = 0.30 m✓
[2]
v = fλ = 250 × 0.30 = 75 m s −1 ✓
1
Physics for the IB Diploma – Tsokos © Cambridge University Press & Assessment 2023
PHYSICS FOR THE IB DIPLOMA: COURSEBOOK
II
[2]
d /cm
4
2
0
1
2
3
4
5
t /ms
22
24
Correct shape ✓
Correct period ✓
c
I
[1]
P
✓
[1]
II
✓
4
Luminosity also depends on area ✓
a
[2]
Star Z has a much larger area than X ✓
b
I
[3]
L
4πσ RZ 2 TZ 4
__
Z = ________
= 10 6 ✓
LY
4πσ RY 2 TY 4
____________
4
R
__
Z = 1
0 6 × ______
20000 4 ✓
RY
2500
√
= 6.4 × 10 3
c
I
X: by radiation pressure caused by fusion reactions ✓
[1]
II
Y: by electron degeneracy pressure ✓
[1]
Uniform lines from left to right in the interior ✓
[2]
5
a
Edge effects ✓
b
c
V = ________
240 −2 = 2.2 × 10 4 N C −1 ✓
E = __
d
____
√
2qV
2
__
__
vp
qp mα
__
v = ____
= __
1 × 4 = √
2 ✓
q
m
2
α
α
p
1 m v 2 ⇒ v = ____
qV = __
m ✓
_____
√
2
2.0 × 10
[1]
[2]
√
Physics for the IB Diploma – Tsokos © Cambridge University Press & Assessment 2023
PHYSICS FOR THE IB DIPLOMA: COURSEBOOK
6
a I
[2]
N = 7.0 × 6.02 × 10 23= 4.2 × 10 24 ✓
4.2 × 10 24 × 3.0 × 10 −30= 1.3 × 10 −5 m 3 ✓
II
RnT ✓
V = ____
[2]
III
7 × 4 = 28 g✓
[1]
One of the assumptions of the kinetic theory of gases states that the
volume of the molecules is negligible compared to the volume of the
gas ✓
[2]
b
P
8.31
× 7.0 × 270 = 5.2 × 10 −2 m 3 ✓
_____________
V =
3.0 × 10 5
V
molecules
Here ______
= ________
1.3 × 10 −2= 2.5 × 10 −4, which is very small ✓
c
P
T1
−5
5.2 × 10
Vgas
P
T2
[2]
P
P1
__1 = __
2 ⇒ T2 = T1 × __
2 ✓
T2 = 270 × ___
5.0 = 450 K✓
3.0
d
[1]
P
0
0
V
Vertical straight line ✓
e I
II
3 RnΔT = __
3 × 8.31 × 7.0 × (450 − 270) = 15706 J✓
ΔU = __
[1]
Realization that Q = ΔU ✓
[2]
2
2
15705
Q = ________________
c = ____
= 3.1 × 10 3 J kg −1 K −1 ✓
mΔT
0.028 × (450 − 270)
f
hc ⇒ λ = __
hc ✓
E = __
λ
[2]
g I
[2] max from
[2]
max
E
−6
1.24
×
1
0
_________
λ =
= 666.6 ≈ 667 nm✓
1.86
Electromagnetic radiation with an infinite rage of wavelengths ✓
With a peak determined by temperature ✓
Radiation emitted by a body at some finite kelvin temperature ✓
Radiation with an intensity proportional to the 4th power of the kelvin
temperature ✓
II
Helium has energy levels separated by 1.86 eV ✓
[3]
This energy difference is unique to helium ✓
The dip implies that photons of this energy are absorbed by helium ✓
3
Physics for the IB Diploma – Tsokos © Cambridge University Press & Assessment 2023
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