This quiz works best with JavaScript enabled. Home > Class 9 > Class 9 Science Chapter 9 Force And Laws Of Motion – Quiz 3 🏠 Homepage 📘 Download PDF Books 📕 Premium PDF Books Class 9 Science Chapter 9 Force And Laws Of Motion Quiz 3 (25 MCQs) Quiz Instructions Select an option to see the correct answer instantly. 1. Newton's first law is also known as A) Law of inertia. B) Law of motion. C) Law of direction. D) None of the above. Show Answer Correct Answer: A) Law of inertia. 2. What effect does friction have on a moving object? A) It causes the moving object to slow and eventually stop. B) It causes the moving object to speed up. C) It keeps the moving object moving in the same direction forever. D) It causes the moving object to turn around and move in the opposite direction. Show Answer Correct Answer: A) It causes the moving object to slow and eventually stop. 3. Why do leaves fall from branches when it is shaken vigorously? A) Inertia of motion. B) Inertia of rest. C) Inertia of direction. D) All of these. Show Answer Correct Answer: B) Inertia of rest. 4. An external influence which changes or tends to change the state of rest or uniform motion of body is called A) Momentum. B) Force. C) Moment of force. D) Pressure. Show Answer Correct Answer: B) Force. 5. According to Newton's Second Law, if you increase the force applied to an object: A) It accelerates more. B) It doesn't move. C) You get more inertia. D) It decelerates. Show Answer Correct Answer: A) It accelerates more. 6. Which of the following statement is not correct for an object moving along a straight path in an accelerated motion? A) Its speed keeps changing. B) Its velocity always changes. C) It always goes away from the earth. D) A force is always acting on it. Show Answer Correct Answer: B) Its velocity always changes. 7. The tendency of an object to resist a change in its state of motion is called: A) Force. B) Momentum. C) Inertia. D) Acceleration. Show Answer Correct Answer: C) Inertia. 8. Which type of force(s) will cause a change in an object's motion? A) Gravity. B) Zero net force. C) Balanced forces. D) Unbalanced forces. Show Answer Correct Answer: D) Unbalanced forces. 9. A force must be physically touching an object in order to act on it. A) True. B) False. C) All the above. D) None of the above. Show Answer Correct Answer: B) False. 10. When a sailor jumps in the forward direction from a small boat the boat moves backwards. Here reaction force is A) In the same direction of applied force. B) Opposite to the direction of applied force. C) Enough data not provided. D) None of these. Show Answer Correct Answer: B) Opposite to the direction of applied force. 11. Keeping applied force constant, if you increase the mass on an object, its acceleration A) Decreases. B) Stays the same. C) Also increases. D) Stops. Show Answer Correct Answer: A) Decreases. 12. What factors does the inertia of body depends? A) It depends on speed. B) It depends on mass. C) It depends on direction. D) None of these. Show Answer Correct Answer: B) It depends on mass. 13. What is the total momentum of the bullet and the gun before firing? A) 0. B) 2. C) 1. D) None of the above. Show Answer Correct Answer: A) 0. 14. FAB= ..... A) -FBA. B) +FBA. C) BOTH AND B. D) NONE OF THESE. Show Answer Correct Answer: A) -FBA. 15. Assertion (A)-When we keep an object on a table, the object exerts a force downwards and the table needs to exert an equal force upwards Reason (R)-For every action there is equal and opposite reaction. A) Both A and R are true and R is the correct explanation of A. B) Both A and R are true but R is not the correct explanation of A. C) A is true but R is false. D) A is false but R is true. Show Answer Correct Answer: A) Both A and R are true and R is the correct explanation of A. 16. The forces are said to be balanced, if net force is ..... A) 0. B) 2. C) 3. D) ALL. Show Answer Correct Answer: A) 0. 17. An object of mass 2 kg is sliding with a constant velocity of 4 m s$^{-1}$ on a frictionless horizontal table. The force required to keep the object moving with the same velocity is A) 32 N. B) 0 N. C) 10 N. D) 2 N. Show Answer Correct Answer: B) 0 N. 18. Can momentum be lost or destroyed? A) Yes. B) No. C) All the above. D) None of the above. Show Answer Correct Answer: B) No. 19. Forces that are equal in size but in opposite directions are called ..... forces. A) Strong. B) Crazy. C) Balanced. D) Unbalanced. Show Answer Correct Answer: C) Balanced. 20. According to the third law of motion, action and reaction. A) Always act on the same body. B) Always act on different bodies in opposite directions. C) Have same magnitude and directions. D) Act on either body at normal to each other. Show Answer Correct Answer: B) Always act on different bodies in opposite directions. 21. A student pushes a box to right with a force of 10N while a young boy pushes the box to the left with a force of 8N. What is the sum of all forces on the box? A) 18N left. B) 18N right. C) 2N right. D) 2N left. Show Answer Correct Answer: C) 2N right. 22. An object of mass 100kg is accelerated uniformly from a velocity of 4 m/s to 8 m/s in 2 seconds. Calculate the initial and final momentum of the object A) 100 kgm/s, 400 kgm./s. B) 400 kgm/s, 400 kgm./s. C) 400 kgm/s, 800 kgm./s. D) 200 kgm/s, 400 kgm./s. Show Answer Correct Answer: C) 400 kgm/s, 800 kgm./s. 23. One newton is equal to A) 10$^{5}$ dyne. B) 10 kg m/s$^{2}$. C) 100 kg m/s$^{2}$. D) 10$^{3}$ dyne. Show Answer Correct Answer: A) 10$^{5}$ dyne. 24. What law is best described by inertia? A) 1 stem. B) Pear. C) 3rd. D) None of the above. Show Answer Correct Answer: A) 1 stem. 25. Which type of force is used when you open a door? A) Frictional force. B) Gravitational force. C) Applied force. D) Magnetism. Show Answer Correct Answer: C) Applied force. ← PreviousNext →Related QuizzesClass 9 Science Chapter 9 Force And Laws Of Motion Quiz 1Class 9 Science Chapter 9 Force And Laws Of Motion Quiz 2Class 9 Science Chapter 9 Force And Laws Of Motion Quiz 4Class 9 Science Chapter 9 Force And Laws Of Motion Quiz 5Class 9 Science Chapter 9 Force And Laws Of Motion Quiz 6Class 9 Science Chapter 9 Force And Laws Of Motion Quiz 7Class 9 Science Chapter 9 Force And Laws Of Motion Quiz 8Class 9 Science Chapter 9 Force And Laws Of Motion Quiz 9Class 9 Science Chapter 9 Force And Laws Of Motion Quiz 10Class 9 Science Chapter 9 Force And Laws Of Motion Quiz 11 🏠 Back to Homepage 📘 Download PDF Books 📕 Premium PDF Books