Try SteamTicket free: 20 practice questions, no signup. Finish a sample and unlock a welcome discount. Pick your class →

4A practice exam › Unit A-1

4A A-1: Elementary Mechanics and Dynamics

49 practice questions in this unit. Each practice set pulls 20 at a time, so you keep seeing new questions as you go.

What this unit covers: Forces and moments, simple machines, velocity and acceleration, work and power, friction, stress and strain.

Exam theme: Science and calculations. Commonly reported share of the 100-question 4A exam: about 7 questions (unofficial; SOPEEC and ABSA do not publish per-unit counts). See the 4A exam breakdown.

2 free 4A A-1 questions, explained

Original exam-style questions written to the public syllabus, from our free public sample. They are not questions from a real exam.

1. A body travels a distance of 1000 m in 65 seconds at a constant rate. What is its average velocity?

  • A. 15.4 m/s
  • B. 18.2 m/s
  • C. 65.0 m/s
  • D. 12.5 m/s
Show the answer and explanation

Answer: A. Average velocity equals displacement divided by time: 1000 m ÷ 65 s ≈ 15.38 m/s, which rounds to 15.4 m/s. The choice of 65.0 m/s is a common error in which the student reads the time value (65 s) directly as a speed without performing the division.

Why the other options are not the answer

  • B. 18.2 m/s would mean 1000 m in about 55 s, not 65 s.
  • C. 65.0 m/s reads the time (65 s) as the speed without dividing.
  • D. 12.5 m/s would mean 1000 m in 80 s, not 65 s.

Question ID KE-A01-C01-Q001 · Unit A-1: Elementary Mechanics and Dynamics · Report an error

2. A chain drive uses a 300 mm diameter drive sprocket and a 1000 mm diameter driven sprocket. If the drive shaft turns at 890 rev/min, what is the rotational speed of the driven shaft?

  • A. 595 rev/min
  • B. 267 rev/min
  • C. 2967 rev/min
  • D. 445 rev/min
Show the answer and explanation

Answer: B. Chain drive speed ratio follows the same inverse-diameter rule as gear drives: N_driven = N_driver × (D_driver / D_driven) = 890 × (300/1000) = 267 rev/min. The driven sprocket is larger, so it turns more slowly. Inverting the diameters gives approximately 2967 rev/min, which is the most common error.

Why the other options are not the answer

  • A. 595 rev/min does not follow from 890 × 300/1000.
  • C. 2967 rev/min inverts the diameter ratio (890 × 1000/300); the larger driven sprocket must turn slower, not faster.
  • D. 445 rev/min simply halves the speed instead of applying the 300/1000 diameter ratio.

Question ID KE-A01-C09-Q005 · Unit A-1: Elementary Mechanics and Dynamics · Report an error

Try 20 free 4A questions 4A practice exam overview

A-2: Elementary Physical, Chemical, and Thermodynamic Principles →

All 4A units