Exercise CBSE-Class IX Science Motion General Instructions: (i) (ii) (iii) (iv) Question no. 1-15 are very short answer questions. These are required to be answered in one sentence each. Questions no. 16-30 are short answer questions. Answers to them should normally not exceed 70 words each. Questions no. 31-45 are long answer questions. Answer to them should normally not exceed 100 words each. Answer should be brief and to the point and the above limits should be adhered to as far as possible. Very short answer type (1 mark) Question 1. Question 2. Question 3. Question 4. Question 5. Question 6. Question 7. Question 8. Question 9. State the condition under which the distance covered and displacement of moving object will have the same magnitude. A particle is moving in a circular path of radius r. What will be the displacement after half a circle? Anil went from home to school 2 km away. On finding school closed, he returned to home immediately. What is his net displacement and distance covered? Sunil takes 10 minutes to walk from his house to school. If his average speed of walking is 6 km/h, calculate the distance between the school and his house. The speed of a train is 36 km/h. what is its speed in m/s? An object covers 10 m in first 2 seconds and then 25 m in 4 seconds. Is this motion uniform or non-uniform? Why? Can speed of an object be negative? Name the instrument used for measuring the distance covered by a vehicle during a given time. Name the instrument fitted in automobiles for measuring its instantaneous speed.
Question 10. Question 11. Question 12. Question 13. Question 14. Question 15. Define retardation. Give an example of uniform and non-uniform motion. Draw the velocity-time graph for uniform motion along a straight line. What is the value of acceleration of a body at rest? Name the quantity which is measured by the area occupied under the velocity-time graph. What does the slope of speed-time graph represents? Short answer type Section B (2 & 3 marks) (3-4 marks each) Question 16. Figure shows the velocity-time graph of an object. Calculate its acceleration. Question 17. Question 18. Question 19. Question 20. An object travels 10 m in 2 sec and then another 10 m in 1 sec. What is the average speed of the object? The odometer of a car reads 1000 km at the start of a trip and 1600 km at the end of the trip. The trip took 6 hours; calculate the average speed of the car in m/s. A car moves with a speed of 10 km/h for half an hour, 20 km/h for one hour and 50 km/h for 2 hours. Calculate the average speed of the car. A train accelerates uniformly from 18 km/h to 36 km/h in 10 s. Find the distance travelled.
Question 21. Given figure show the distance covered by an object at different times. Draw distance-time graph. Question 22. Figure shows the speed-time graph for an object: Calculate the total time for which the speed of an object remains constant and the total time for which speed is variable. Question 23. Calculate the total distance covered by an object. Question 24. Rajdhani express starting from rest attains a velocity of 108 km/h in 20 minutes. Find the acceleration and the distance travelled by the train for attaining this velocity assuming the acceleration to be uniform.
Question 25. Question 26. Question 27. An object moving with uniform acceleration acquired a velocity 12 m/s in 2 s and 18 m/s in 4 s. Calculate the initial velocity of the body. A car moving along a straight road increases its speed uniformly from 15 m/s to 30 m/s over a time interval of 1 minute. Find the acceleration and the distanced by it in this time interval. What type of motion is represented by each of the following graphs? Question 28. Question 29. Question 30. A motorcycle is being driven at a speed of 20 m/s when brakes are applied to bring it to rest in 5 s. find the deceleration produced. The velocity-time graph is a horizontal straight line. What does this tell you about the velocity and acceleration? A car moving along a straight road increases its speed uniformly from 15 m/s to 30 m/s over a time interval of 1 minute. Calculate the acceleration and the distance travelled by it during this time interval. Long answer type (5 marks) Question 31. A car is moving on a straight road with uniform speed. It covers 150 m in 5 seconds. a. Calculate its average speed? b. Calculate the distance covered by it in 1 second. c. Calculate the distance covered by it in 10 second. d. How much time does it take to cover 240 m distance? e. How much time does it take to cover 100 m distance? Question 32. Question 33. Differentiate between distance and displacement.draw distance-time graph for an object moving with uniform motion. An object starts moving in a straight line with a velocity u under uniform acceleration a. After time t it acquires velocity v. Draw velocity-time graph and obtain the following equations from it: a. v= u + at b. S = ut + at
Question 34. Question 35. Establish the equation for position-velocity relation from the velocity-time graph. a. Calculate the acceleration of an object. b. Find the total distance covered by the body during its motion. Question 36. Derive the equation S = ut + at by the graphical method, where the symbols have their usual meanings. Question 37. Question 38. a. Derive the equation v = u + at by the graphical method, where the symbols have their usual meanings. b. A body starting from rest moves with uniform acceleration. What is the value of acceleration if it travels 200 m in 10 s. Define uniform circular motion. Give two examples of uniform circular motion. Is uniform circular motion an accelerated motion? If yes, what is the direction of the acceleration?
Question 39. a. What is the initial and final velocity of an object? b. Which portion of the graph shows that an object is moving with constant velocity? c. Which portion of the graph indicates uniform acceleration? d. Which portion of the graph indicates retardation? e. Calculate the acceleration of an object? Question 40. a. Calculate the acceleration of an object. b. Find the total distance covered by the body during its motion. Question 41. What are the three equations of uniformly accelerated motion? A car starting from rest acquires a velocity of 36 km/hour in 5 second. Find the acceleration and the distance travelled in this time.
Question 42. Study the velocity-time graph of a body given and answer the following questions: a. What type of motion is represented by AB? b. What type of motion is represented by BC? c. What type of motion is represented by CD? d. Calculate the acceleration of the body? e. Find out the retardation of the body. Question 43. A car is moving in a straight line with uniform acceleration. The speed of the car at different instants of time is shown in the following table: Speed (m/s) 0 10 20 30 40 50 Time (s) 0 2 4 6 8 10 Draw the speed-time graph. Find the acceleration and the distance travelled by the car in 10 seconds. Question 44. Question 45. Define the following terms: a. Uniform and non-uniform motion b. Speed and velocity c. Average speed d. Uniform speed e. Acceleration Define the term uniform acceleration. Give one example. A car driver travelling at 10 m/s applies break and brings the car to rest in 20 s. Find the retardation.