Class 9 Science Chapter 6: How Forces Affect Motion — practice questions with answers
Free practice for Class 9 Science, Chapter 6: How Forces Affect Motion. Try the solved questions below, then take a free test with instant marking and explanations.
57 questions19 easy, 28 medium, 10 hardNCERT · CBSE · State boards
Sample questions with solutions
Q1. Which of these can a force do?
- All of: start motion, change speed or direction, and change shape
- Only start motion
- Only change shape
- Nothing to a moving object
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Answer: A. All of: start motion, change speed or direction, and change shape
Why: e.g. a bat changes a ball’s direction; squeezing changes a lemon’s shape. [p.94]
Why: e.g. a bat changes a ball’s direction; squeezing changes a lemon’s shape. [p.94]
Q2. Two people push a stalled car in the same direction with 200 N and 150 N. What is the net force (N)?
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Answer: 350 (± 0)
Why: Same direction: add them. [p.96]
Why: Same direction: add them. [p.96]
Q3. In a tug of war, one team pulls with 900 N and the other with 750 N in the opposite direction. What is the net force (N)?
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Answer: 150 (± 0)
Why: Opposite: subtract; direction of the larger force. [p.96]
Why: Opposite: subtract; direction of the larger force. [p.96]
Q4. Why does a moving object eventually stop if you stop pushing it?
- Friction acts opposite to its motion and slows it down
- Objects naturally want to stop
- Gravity pushes it backward
- Air pushes it forward
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Answer: A. Friction acts opposite to its motion and slows it down
Why: Without friction it would keep moving. [p.98–99]
Why: Without friction it would keep moving. [p.98–99]
Q5. What does Newton’s first law of motion state?
- An object stays at rest or moves with constant velocity unless a net force acts on it
- Force equals mass times acceleration
- Every action has an equal and opposite reaction
- Objects always slow down
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Answer: A. An object stays at rest or moves with constant velocity unless a net force acts on it
Why: The tendency to resist change is inertia. [p.101, p.112]
Why: The tendency to resist change is inertia. [p.101, p.112]
Q6. What force gives a 1500 kg car an acceleration of 2 m/s² (N)?
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Answer: 3000 (± 0)
Why: F = ma = 3000 N. [p.106]
Why: F = ma = 3000 N. [p.106]
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Frequently asked questions
How many practice questions are there for Class 9 Science Chapter 6: How Forces Affect Motion?
57 questions (19 easy, 28 medium, 10 hard). A few are solved on this page; the free test shows the answer and explanation for every question after you submit.
Is this chapter from the NCERT book?
Yes — it follows the NCERT Class 9 Science syllabus, used by CBSE and many state boards.