CIE iGCSE Co-Ordinated Science P1.3 Mass and weight Exam Style Questions Paper 3
Question
Topic codes:
• Topic P6.1 — The Solar System (Part (a))
• Topic P5.2.3 — Radioactive decay (Part (b))
• Topic P1.4 — Density (Part (c)(i), (c)(iii) & (d))
• Topic P1.3 — Mass and weight (Part (c)(ii))
• Topic P1.5.1 — Effects of forces (Part (d))
▶️ Answer/Explanation
(a) Planets in order from closest to the Sun:
Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune
The eight planets of our Solar System in order of increasing distance from the Sun are: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune. Pluto is classified as a dwarf planet and is not included.
(b) neutron → proton + electron (β⁻ particle)
During β⁻ emission, a neutron in the nucleus of an atom decays into a proton and an electron (β⁻ particle). The electron is emitted from the nucleus, and the proton remains in the nucleus, increasing the atomic number by 1.
(c)(i) Volume = 56 cm³
Volume = length × width × height = 7.0 × 4.0 × 2.0 = 56 cm³
(c)(ii) Mass calculation:
Weight = mass × gravitational field strength
\(W = m \times g\)
\(m = \frac{W}{g} = \frac{1.47}{9.8} = 0.15\) kg
Converting from kg to g: 0.15 × 1000 = 150 g
(c)(iii) Density = 2.7 g/cm³
Density = mass ÷ volume
\(\rho = \frac{150}{56} = 2.68 \approx 2.7\) g/cm³
(d) The density of granite is greater than the density of water.
An object will sink in a fluid if its density is greater than the density of the fluid. The granite block has a density of 2.7 g/cm³, which is greater than the density of water (1.0 g/cm³). Therefore, the upward buoyant force from the water is less than the weight of the block, causing it to sink.
Question
- travels through space
- slows down through the Earth’s atmosphere
- hits the Earth’s surface.
Isotopes are atoms of the same element which have the same …………………… number but a different …………………… number.
Most-appropriate topic codes (Cambridge IGCSE Co-ordinated Sciences 0654):
• Topic P1.2 — Motion (Part (a))
• Topic P1.3 — Mass and weight (Part (b)(i))
• Topic P1.4 — Density (Part (b)(ii))
• Topic P4.1 — Simple phenomena of magnetism (Part (c))
• Topic C2.3 — Isotopes (Part (d))
▶️ Answer/Explanation
(a)(i) 30,000 m/s
Reading the graph at the flat (constant speed) section before the meteorite enters the atmosphere gives the maximum speed.
The speed remains constant at \(30{,}000 \, \text{m/s}\) while travelling through space where there is no air resistance.
(a)(ii) 20 s
The meteorite hits the surface when its speed reaches zero on the graph.
Reading from the graph, this occurs at \(t = 20 \, \text{s}\).
(a)(iii) Friction / air resistance
As the meteorite passes through the Earth’s atmosphere, air molecules collide with it.
This creates a resistive force (air resistance/friction) that acts opposite to the direction of motion, slowing it down.
(b)(i) \(3.3 \times 10^7 \, \text{kg}\)
Using the formula \(W = mg\), rearranged to: \(m = \dfrac{W}{g}\)
\(m = \dfrac{3.3 \times 10^8}{10} = 3.3 \times 10^7 \, \text{kg}\)
(b)(ii) 7900 kg/m³
Using \(\rho = \dfrac{m}{V}\):
\(\rho = \dfrac{3.3 \times 10^7}{4200} = 7857 \approx 7900 \, \text{kg/m}^3\)
Units: \(\text{kg/m}^3\)
(c) Place the iron in a solenoid (coil) and pass a direct current (d.c.) through the coil.
The magnetic field created by the current-carrying coil aligns the magnetic domains in the iron.
Alternatively, placing the iron in the direction of the Earth’s magnetic field and hammering it gently can also magnetise it.
(d)(i) proton (atomic) number … nucleon (mass) number
Isotopes are atoms of the same element with the same proton/atomic number but a different nucleon/mass number.
They differ only in the number of neutrons in the nucleus.
(d)(ii)
Neutrons = mass number − proton number
Isotope A: \(54 – 26 = \mathbf{28}\) neutrons
Isotope B: \(56 – 26 = \mathbf{30}\) neutrons