{"id":31534,"date":"2026-05-20T17:10:11","date_gmt":"2026-05-20T11:40:11","guid":{"rendered":"https:\/\/mycbseguide.com\/blog\/?p=31534"},"modified":"2026-05-20T17:10:52","modified_gmt":"2026-05-20T11:40:52","slug":"how-forces-affect-motion-ncert-solutions-class-9-science-exploration","status":"publish","type":"post","link":"https:\/\/mycbseguide.com\/blog\/how-forces-affect-motion-ncert-solutions-class-9-science-exploration\/","title":{"rendered":"How Forces Affect Motion – NCERT Solutions Class 9 Science Exploration"},"content":{"rendered":"\n

How Forces Affect Motion – NCERT Solutions Class 9 Science Exploration includes all the questions with solutions given in NCERT Class 9 Science Exploration<\/a> textbook.<\/p>\n\n\n\n

NCERT Solutions Class 9<\/h2>\n\n\nEnglish Kaveri<\/a>\n\n\nHindi Ganga<\/a>\n\n\nSanskrit Sharada<\/a>\n\n\nMaths Ganita Manjari<\/a>\n\n\nScience Exploration<\/a>\n\n\nSocial Understanding Society<\/a>\n\n\n\n

How Forces Affect Motion \u2013 NCERT Solutions<\/h2>\n\n\n\n
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Q.1: Why does a canoe move forward when the canoeist pushes water backwards with their paddle and why does it move faster when they push harder?<\/strong><\/p>\n\n\n\n

Solution: When the canoeist pushes water backward with the paddle, the water exerts an equal and opposite force on the canoe, pushing it forward. This is why the canoe moves ahead. When the canoeist pushes the water harder, a larger force is applied backward, so the water gives a larger forward reaction force, making the canoe accelerate more and move faster.<\/p>\n\n\n\n

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Q.2: Suppose the same canoeist uses the same paddle force in two different canoes, one empty and one carrying another passenger. In which case will the canoe move faster?<\/strong><\/p>\n\n\n\n

Solution: The canoe with only the canoeist (empty canoe) will move faster.
Because the same force produces more acceleration when the mass is smaller. The canoe with an extra passenger has greater mass, so it accelerates less and moves slower.<\/p>\n\n\n\n

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Q.3: A weightlifter lifts a barbell. List two forces that are acting on the barbell. Are these forces balanced if the weightlifter keeps the barbell steady?<\/strong>
<\/p>\n\n\n\n

Solution: Forces acting on the barbell:<\/p>\n\n\n\n

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  1. Downward force due to gravity (weight of barbell)<\/li>\n\n\n\n
  2. Upward force applied by the weightlifter<\/li>\n<\/ol>\n\n\n\n

    Yes. When the barbell is held steady, both forces are equal in magnitude and opposite in direction, so the net force is zero and the forces are balanced.<\/p>\n\n\n\n

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    Q.4: Two players R and S are participating in an arm-wrestling match. At the instant, when the arms tilt to the front direction (out of the page towards you), are the forces exerted by the players balanced? If not, which player exerted the larger force?<\/strong>
    <\/p>\n\n\n\n

    Solution: No, the forces are not balanced at that instant because the arms are moving (tilting), so there is a net force.<\/p>\n\n\n\n

    The player whose arm is moving forward (towards you \/ out of the page) is exerting the larger force and is winning the match.<\/p>\n\n\n\n

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    Q.5: An object is moving with a constant velocity. Is there a net force acting upon it?<\/strong><\/p>\n\n\n\n

    Solution: No, there is no net force acting on the object.
    According to Newton’s First Law of Motion, an object moving with constant velocity continues in uniform motion unless acted upon by an external unbalanced force. Since the velocity is constant, the acceleration is zero. From Newton’s Second Law, {tex}F=m a{\/tex}, if {tex}a=0{\/tex}, then net force {tex}F=0{\/tex}.<\/p>\n\n\n\n

    Therefore, no net force acts on the object.<\/p>\n\n\n\n

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    Q.6: Suppose, no net force is acting on an object. Which of the following situations are possible?<\/strong><\/p>\n\n\n\n

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    1. Object remains at rest if at rest.<\/li>\n\n\n\n
    2. Object keeps moving with a constant velocity if already moving.<\/li>\n\n\n\n
    3. Object is moving with a constant acceleration.<\/li>\n<\/ol>\n\n\n\n

      Solution: If no net force is acting on an object, then its acceleration is zero (Newton\u2019s First Law of Motion).<\/p>\n\n\n\n

      Now, analysing the given situations:<\/p>\n\n\n\n

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      1. Object remains at rest if at rest:<\/strong>
        Yes, this is possible because without any net force, an object at rest continues to remain at rest.<\/li>\n\n\n\n
      2. Object keeps moving with a constant velocity if already moving:<\/strong>
        Yes, this is also possible because in absence of net force, a moving object continues with uniform velocity.<\/li>\n\n\n\n
      3. Object is moving with a constant acceleration:<\/strong>
        No, this is not possible because constant acceleration requires a net force to act on the object.<\/li>\n<\/ol>\n\n\n\n

        Conclusion:<\/strong> Situations (i) and (ii) are possible, but (iii) is not possible.<\/p>\n\n\n\n

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        Q.7: In the real world, it is difficult to find a situation where no forces are acting on an object. But by applying additional forces, a condition can be achieved where the net force on the object is zero. Explain with the help of an example.<\/strong><\/p>\n\n\n\n

        Solution: In real life, multiple forces usually act on an object. However, if these forces balance each other such that their resultant (net force) is zero, the object behaves as if no force is acting on it.<\/p>\n\n\n\n

        Example:<\/strong>
        When a book is kept on a table, two forces act on it:<\/p>\n\n\n\n