Class 9 Practice Level 2 – Force and Laws of Motion – Set 1 Leave a Comment / By Gulam Hamza / July 8, 2024 Class 9 Practice Level 2 - Force and Laws of Motion - Set 1 Total questions: 25 1. A 10 kg object is subjected to a net force of 50 N. What is the acceleration of the object? 5 m/sÂ² 10 m/sÂ² 50 m/sÂ² 100 m/sÂ² None 2. A car of mass 1000 kg is moving with a velocity of 20 m/s. What is its momentum? $ \displaystyle {20,000\text{ }kg\cdot m/s}$ $ \displaystyle {10,000\text{ }kg\cdot m/s}$ $ \displaystyle {5,000\text{ }kg\cdot m/s}$ $ \displaystyle {40,000\text{ }kg\cdot m/s}$ None 3. If the mass of an object is doubled while the net force on it remains constant, what happens to the acceleration? It doubles It halves It remains the same It becomes zero None 4. Which type of friction occurs when a box is sliding on a rough surface? Static friction Sliding friction Rolling friction Fluid friction None 5. When a bullet is fired from a gun, the gun recoils. This is an example of: Newton's First Law Newton's Second Law Newton's Third Law Law of Conservation of Energy None 6. What is the impulse experienced by a 5 kg object subjected to a force of 10 N for 2 seconds? 5 Ns 10 Ns 20 Ns 40 Ns None 7. What provides the centripetal force for a car taking a turn on a flat road? Gravitational force Frictional force Normal force Applied force None 8. An object will not change its state of motion unless acted upon by: Balanced forces Unbalanced forces Equal forces Net force is zero None 9. In an elastic collision, which of the following is conserved? Momentum only Kinetic energy only Both momentum and kinetic energy Neither momentum nor kinetic energy None 10. If the distance between two objects is halved, the gravitational force between them: Doubles Halves Quadruples Remains the same None 11. Two forces, 20 N and 30 N, act on an object in opposite directions. The net force on the object is: 10 N 50 N 20 N 30 N None 12. What is the acceleration due to gravity of an object in free fall near the Earth's surface? 9.8 m/sÂ² 10 m/sÂ² 1 m/sÂ² 9.8 km/sÂ² None 13. According to Newtonâ€™s Third Law, the reaction force to a hammer striking a nail is: The nail pushing back on the hammer The hammer pushing forward The nail moving None of the above None 14. In a tug of war, the rope exerts which type of force on the participants? Gravitational force Frictional force Tension force Normal force None 15. Which of Newtonâ€™s laws explains the motion of a rocket? First Law Second Law Third Law None of the above None 16. If a force of 100 N is applied to a 25 kg object, what is the acceleration? 2 m/sÂ² 4 m/sÂ² 8 m/sÂ² 10 m/sÂ² None 17. Work done by a force is equal to the force multiplied by Distance Time Velocity Acceleration None 18. What effect does increasing the roughness of a surface have on friction? Decreases friction Increases friction Has no effect on friction Changes the direction of friction None 19. Which of the following forces provides the centripetal force necessary for a satellite to orbit Earth? Gravitational force Magnetic force Frictional force Electrostatic force None 20. The mass of an object on the moon compared to its mass on Earth is: More Less The same Double None 21. Two forces of 10 N and 20 N act on an object at right angles. The resultant force is: 10 N 20 N 22.4 N 30 N None 22. If the velocity of an object changes from 10 m/s to 20 m/s in 2 seconds, what is its acceleration? 5 m/sÂ² 10 m/sÂ² 15 m/sÂ² 20 m/sÂ² None 23. According to the work-energy theorem, the work done on an object is equal to its change in: Kinetic energy Potential energy Thermal energy Chemical energy None 24. An ice skater pushes against the ice, and the ice pushes back with equal force. This demonstrates: Newton's First Law Newton's Second Law Newton's Third Law Law of Inertia None 25. Which method is commonly used to reduce friction between moving parts in machines? Increasing roughness Applying lubricants Adding more weight Using larger surfaces None 1 out of 25 Time's up