CBSE Class 8 Science Chapter 9 Friction Long Answer Questions
Question 1. Raju wanted to find out which one of the four surfaces produces the greatest friction. He pushed the same toy car on the four surfaces, separately.
” CBSE Class 8 Science Chapter 9 LAQs “
Raju noted the distance travelled by car on each surface before stopping.
1. On which surface did the car experience the greatest friction?
- Surface 1
- Surface 2
- Surface 3
- Surface 4
Answer: 3. Surface 3
” Friction Class 8 “
2. What must be kept the same in the activity to compare the distances travelled by the car?
Answer: The Toy car and pushing force must be kept the same in the activity to compare the distance travelled by the car.
Read And Learn More CBSE Class 8 Science Long Answer Questions
3. What will happen to the car if it continues to move on the surface for 1 h?
- The wheels will get hard.
- The wheels will become hot.
- The wheels will shrink in size.
- The wheels will change shape
Answer: 2. The wheels will become hot.
Question 2. The picture shows four different rubber tubes.
” Types of Friction Class 8 “
1. Which tube will experience the least friction while rolling on a surface? Explain your answer.
Answer: Tube 2 experiences the least friction while rolling on n surface because the area of contact between the two surfaces is less in the case of Tube 2.
2. Which of these would affect the amount of friction generated on a moving object? Circle ‘Yes’ or ‘No’ for the correct response.
Answer: (a) Yes, (b) Yes, (c) Yes
” Rolling Friction Experiment “
Question 3. Anshu lets a marble roll freely on four rough wooden planks. The table shows the time taken by the marble to reach the bottom of each plank.
” Surface Texture and Friction “
1. What could be the value of X in the table?
- 2s
- 3s
- 4s
- 5s
Answer: 4. 5s
” Sliding Friction Experiment “
2. Anshu polished all four planks to smooth the surfaces. She repeated her activity on the polished planks. Will there be any change in the results? Explain your answer.
Answer: Yes, results will change. Polishing the surface makes it smooth, then the friction between the marble and the plank decreases, which results in a decrease in the time taken by the marble to reach the bottom.