Ncert – class 9- science – Chapter 8 – Force and Laws of Motion 2 Welcome to your Ncert – class 9- science – Chapter 8 – Force and Laws of Motion 2 1. Match the following with correct response.(1) Cause of acceleration(2) Quantitative measure of inertia(3) powder applied on carom board(4) Tyres of vehicles made Rough (A) Mass(B) Increases friction(C) Decreases friction(D) Force 1-D, 2-A, 3-C, 4-B 1-A, 2-C, 3-B, 4-D 1-C, 2-B, 3-D, 4-A 1-B, 2-D, 3-A, 4-C None 2. Identify the incorrect statement. The weight of a body always acts towards the centre of the Earth. Frictional force always acts parallel to the surface of contact. The tension of a string always pulls a body. The spring force always pushes a body. None 3. A carpenter exerts a force of magnitude 1.5 N at right angles on the surface of a nail of mass 3 gram to drive it into a wooden plank. If the plank offers a resistive force of 0.6 N and the time of interaction of hammer and the nail 0.01 s, the depth through which the nail penetrates is 15m 1.5 mm 1.5 cm 15 cm None 4. It is due to which of the following reasons that a scooter generally slips on an oily road? Friction between tyres and road decreases. All the above. Friction between tyres and road increases. Friction between tyres and road remain same. None 5. The people in a bus are pushed backwards when the bus starts suddenly because of Inertia due to rest External force Inertia due to motion Inertia due to direction None 6. Two spring balances pull each other in opposite directions. If the reading of one spring balance is 2 N, the reading shown by the second spring balance will be 2.5 N 4 N 2 N 3.5 N None 7. An Object moving along a straight path with an accelerated motion. The correct statement about the object-A Its velocity keeps changingB Its speed keeps changingC A force is always acting on itD Its mass keeps on changing All of these (a) and (b) are correct (b) and (c) are correct (a), (b) and (c) are correct None 8. When a force is exerted on an object, it can change its-A StateB PositionC ShapeD Direction All of these (a), (b) and (c) are correct (b) and (c) are correct (a) and (b) are correct None 9. A force of 10 N acts on a ball moving on a surface. The force of friction that must act between the surface of the ball and the surface so that the ball keeps on moving with constant velocity over the surface must be 100 N Zero 20 N 10 N None 10. Which one is correct if a bullet is fired from a rifle? Bullet moves in the backward direction and rifle moves in the forward direction. There is no motion of bullet and rifle. Bullet and rifle both move in the backward direction. Rifle moves in the backward direction and bullet moves in the forward direction. None 11. Find the time for which a force of 1kgwt acts on a body of mass 1 kg moving with a uniform speed of 4m/s to stop the body. 0.4 s 0.6 s 0.2 s 0.8 s None 12. Statement A: Gravitational force is the weakest force in nature.Statement B: Electrostatic force is an example of non – contact forces.Which of the above two statements is true? Both the statement a and b are true. Statement A is true Statement B is true Neither statement A nor B are true None 13. Which of the following is true about action and reaction forces acting on two bodies of equal masses? Action and reaction forces are equal and opposite and produce unequal and opposite acceleration. Action and reaction forces are equal and opposite and produce equal and opposite acceleration. Action and reaction forces are unequal and opposite and produce unequal and opposite acceleration. Action and reaction forces are unequal and opposite and produce equal and opposite acceleration. None 14. Match the following with correct response.(1) Action and reaction(2) Magnitude of force(3) Momentum(4) Resultant of balanced force (A) No acceleration(B) Newton’s second law(C) Act on different objects(D) Vector quantity 1-A, 2-C, 3-B, 4-D 1-D, 2-A, 3-C, 4-B 1-B, 2-D, 3-A, 4-C 1-C, 2-B, 3-D, 4-A None 15. If an object moves with a uniform velocity we can conclude that no unbalanced force acts on it an unbalanced force acts on the body there is no force acting on the body it has uniform acceleration None Time's up Please Share This Share this content Opens in a new window Opens in a new window Opens in a new window Opens in a new window Opens in a new window Opens in a new window Opens in a new window Opens in a new window Opens in a new window Opens in a new window Leave a Reply Cancel replyCommentEnter your name or username to commentEnter your email address to commentEnter your website URL (optional) Save my name, email, and website in this browser for the next time I comment.
