Chapter 8: Force and Laws of Motion — Online MCQ Test
SCIENCE · CLASS 9th · Karnataka State Board
Practice Chapter 8: Force and Laws of Motion with a free chapter-wise online MCQ test.
This chapter covers: This chapter details balanced unbalanced forces Newton three laws of motion inertia mass momentum and conservation of momentum principles..
AI-generated questions from basic to board-exam level, with instant results and explanations.
Chapter 8: Force and Laws of Motion — Important Questions & Answers
Which of the following is a vector quantity?
- A. Mass
- B. Force
- C. Speed
- D. Time
Answer: B. Force
Force has both magnitude and direction, so it is a vector quantity. Mass, speed, and time are scalar quantities.
Force has both magnitude and direction, so it is a vector quantity. Mass, speed, and time are scalar quantities.
The SI unit of momentum is:
- A. kg m/s
- B. N/m
- C. kg/m
- D. N s/m
Answer: A. kg m/s
Momentum equals mass × velocity, so its unit is kg × m/s = kg m/s.
Momentum equals mass × velocity, so its unit is kg × m/s = kg m/s.
A force of 10 N acts on a body of mass 2 kg. The acceleration produced is:
- A. 2 m/s²
- B. 5 m/s²
- C. 8 m/s²
- D. 20 m/s²
Answer: B. 5 m/s²
Using F = ma, acceleration = F/m = 10/2 = 5 m/s².
Using F = ma, acceleration = F/m = 10/2 = 5 m/s².
A body of mass 4 kg moving with velocity 3 m/s has momentum equal to:
- A. 7 kg m/s
- B. 12 kg m/s
- C. 1.33 kg m/s
- D. 24 kg m/s
Answer: B. 12 kg m/s
Momentum is mass × velocity = 4 × 3 = 12 kg m/s.
Momentum is mass × velocity = 4 × 3 = 12 kg m/s.
A 2 kg cart moving at 6 m/s collides with a stationary 1 kg cart and they move together after collision. If momentum is conserved, their common velocity is:
- A. 2 m/s
- B. 4 m/s
- C. 6 m/s
- D. 12 m/s
Answer: A. 2 m/s
Initial momentum = 2 × 6 + 1 × 0 = 12 kg m/s. Combined mass = 3 kg, so velocity = 12/3 = 4 m/s.
Initial momentum = 2 × 6 + 1 × 0 = 12 kg m/s. Combined mass = 3 kg, so velocity = 12/3 = 4 m/s.