CIE iGCSE Co-Ordinated Science P1.5.1 Effects of forces Exam Style Questions Paper 3
Question
Most-appropriate topic codes (Cambridge IGCSE Coordinated Sciences 0654):
• Topic P1.5.1 — Effects of forces (Part (a)(i), (a)(ii), (a)(iii))
• Topic P3.4 — Sound (Part (b)(i), (b)(ii))
• Topic P4.3.2 — Series and parallel circuits (Part (c)(i), (c)(ii), (c)(iii))
• Topic P3.2.1 — Reflection of light (Part (d))
▶️ Answer/Explanation
(a)(i) D
Force D opposes the motion of the car and is partly caused by air resistance (drag), which increases with speed.
(a)(ii) weight is the gravitational force on an object that has mass / definition of mass (not weight)
The statement describes mass (the quantity of matter). Weight is the gravitational force acting on an object due to its mass in a gravitational field.
(a)(iii) 2000 (N) and (constant speed so) no resultant force
At constant speed, the driving force (B) equals the resisting force (D) because there is no resultant force and no acceleration. Therefore B = D = 2000 N.
(b)(i) decreases
The amplitude of a sound wave is related to loudness. A quieter sound has a smaller amplitude.
(b)(ii) decreases
Pitch is related to frequency. A lower frequency sound has a lower pitch. The engine note becomes lower in pitch.
(c)(i) battery
The battery provides the electromotive force (voltage) that causes current to flow through the circuit.
(c)(ii) 8 (A); current in main part of circuit is greater than current in either branch
In a parallel circuit, the total current from the source equals the sum of the currents in each branch. Current at X = 4 + 4 = 8 A.
(c)(iii) full voltage across both lamps OR if one lamp fails, the other will still work
Parallel connection ensures each lamp receives the full supply voltage and operates independently. If one fails, the other continues to work.
(d) any two from: same size; same distance from mirror; laterally inverted
A plane mirror produces an image that is: same size as the object, same distance behind the mirror as the object is in front, and laterally inverted (left-right reversed). The image is also virtual and upright.
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.