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Secondary 4 Physics Practice Paper: Kinematics, Forces and Newton Laws, Work Energy and Power, Momentum and Collisions, Heat and Specific Heat Capacity, Waves and Lenses (100 marks)

Secondary 4 Physics Practice Paper: Kinematics, Forces and Newton Laws, Work Energy and Power, Momentum and Collisions, Heat and Specific Heat Capacity, Waves and Lenses (100 marks)

  • 2026-11-14

Physics – Secondary 4 – Practice Paper

S4 Physics practice paper, 24 parts on kinematics, forces, work and power, momentum, specific heat capacity and lenses. All values computed in python.

Paper details S4 Physics practice paper with 24 parts on kinematics, forces, work and power, momentum, specific heat capacity, waves and lenses. Answers with marking points.

Section A: Kinematics and Graphs (16 marks)

A car starts from rest and accelerates uniformly at 2.0 m/s2 for 6 s, then travels at constant speed for 10 s, and finally decelerates uniformly to rest in 5 s.

# Question Answer and marking notes
1 (a) Find the speed of the car at the end of the acceleration stage. Answer: v = 2.0 x 6 = 12 m/s in the direction of motion. (Marking: formula 1, substitution 1, unit 1)
2 (b) Find the total distance travelled in the whole 21 s. Answer: acceleration stage 36 m, constant speed stage 120 m, deceleration stage 30 m, total 186 m. (Marking: 1 mark per stage, 1 for sum, 1 for unit)
3 (c) Find the average speed for the whole journey (3 significant figures). Answer: average speed = 186 / 21 = 8.86 m/s. (Marking: total distance over total time 2, value 1, unit 1)
4 (d) Find the acceleration in the deceleration stage and state its direction. Answer: a = (0 – 12) / 5 = -2.4 m/s2; the negative sign shows it opposes the motion, magnitude 2.4 m/s2. (Marking: formula 1, value 1, direction 2)

Section B: Forces and Newton Laws (16 marks)

A 5 kg block on a rough horizontal table is pulled from rest by a horizontal force of 40 N. The coefficient of kinetic friction is 0.35 and g = 10 m/s2.

# Question Answer and marking notes
5 (a) Find the friction force acting on the block. Answer: f = 0.35 x 5 x 10 = 17.5 N opposing the motion. (Marking: formula 1, value 1, direction 1)
6 (b) Find the acceleration of the block. Answer: net force 22.5 N; a = 22.5 / 5 = 4.5 m/s2. (Marking: net force 1, formula 1, value 2)
7 (c) Find the speed of the block after 4 s. Answer: v = 4.5 x 4 = 18 m/s. (Marking: formula 1, substitution 2, unit 1)
8 (d) If the pulling force is removed at the end of 4 s, find the further distance slid. Answer: deceleration 3.5 m/s2; s = 18^2 / (2 x 3.5) = 46.3 m. (Marking: deceleration 2, formula 1, value 2)

Section C: Work, Energy and Power (16 marks)

A 20 kg crate is pushed 5 m up a smooth incline measured along the incline. The incline makes 30 degrees with the horizontal and g = 10 m/s2.

# Question Answer and marking notes
9 (a) Find the vertical height gained by the crate. Answer: h = 5 x sin 30 = 2.5 m. (Marking: trigonometry 2, value 1)
10 (b) Find the work done against gravity in the process. Answer: W = mgh = 20 x 10 x 2.5 = 500 J. (Marking: formula 1, substitution 2, unit 1)
11 (c) If the whole process takes 4 s, find the average power of the pushing force. Answer: P = 500 / 4 = 125 W. (Marking: formula 1, substitution 2, unit 1)
12 (d) The crate is released from rest at that height and slides down the smooth incline. Find its speed at the bottom. Answer: by energy conservation v = sqrt(2 x 10 x 2.5) = 7.07 m/s. (Marking: energy conservation 2, formula 1, value 2)

Section D: Momentum and Collisions (16 marks)

Trolley A of mass 2 kg moving at 3 m/s collides with stationary trolley B of mass 4 kg. After the collision the two trolleys stick together.

# Question Answer and marking notes
13 (a) Find the common speed of the two trolleys after collision. Answer: momentum conservation gives 6 = 6v, so v = 1 m/s. (Marking: equation 1, substitution 1, value 1)
14 (b) Find the total kinetic energy before the collision. Answer: total KE = 0.5 x 2 x 9 = 9 J. (Marking: formula 1, substitution 2, unit 1)
15 (c) Find the kinetic energy lost in the collision. Answer: KE after = 3 J, so loss = 6 J. (Marking: final KE 2, subtraction 2)
16 (d) If the collision were perfectly elastic, find the velocities of A and B after collision. Answer: A = -1 m/s (rebounds), B = 2 m/s; momentum 6 and KE 9 are both conserved. (Marking: A 2, B 2, check 1)

Section E: Heat and Specific Heat Capacity (16 marks)

A 500 W heater heats 0.5 kg of water from 20 degC to 80 degC. The specific heat capacity of water is 4200 J/(kg K).

# Question Answer and marking notes
17 (a) Find the energy absorbed by the water. Answer: Q = mc dT = 0.5 x 4200 x 60 = 126000 J. (Marking: formula 1, substitution 2, unit 1)
18 (b) Find the time needed in theory. Answer: t = 126000 / 500 = 252 s. (Marking: formula 1, substitution 2, unit 1)
19 (c) If the heating actually takes 300 s, find the efficiency of the heater. Answer: efficiency = 126000 / 150000 = 0.84, i.e. 84 per cent. (Marking: definition 2, calculation 2, percent 1)
20 (d) Explain why the actual time is longer than the theoretical value. Answer: some heat is lost to the surroundings and the container, so less energy heats the water. (Marking: heat loss 2, explanation 1)

Section F: Waves and Lenses (20 marks)

A sound wave of frequency 250 Hz travels in air with wavelength 1.2 m. A convex lens of focal length 10 cm has an object placed 30 cm in front of it.

# Question Answer and marking notes
21 (a) Find the speed of the sound wave. Answer: v = f x wavelength = 250 x 1.2 = 300 m/s. (Marking: formula 1, substitution 2, unit 1)
22 (b) Find the time for the sound wave to travel 510 m. Answer: t = 510 / 300 = 1.7 s. (Marking: formula 1, substitution 2, unit 1)
23 (c) Find the image distance. Answer: 1/v = 1/10 – 1/30 = 1/15, so v = 15 cm behind the lens. (Marking: formula 2, substitution 2, value 2)
24 (d) Find the magnification and state the nature of the image. Answer: m = 15 / 30 = 0.5; the image is inverted, diminished and real. (Marking: magnification 2, inverted 1, diminished 1, real 2)

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