Can anyone answer this question please......... urgently as it is my school's homework.
Answers
Friction experiment
Today you will be conducting an experiment with motion, frictional force, and learn how such frictional forces may affect the game of football.
Materials needed:
Three textbooks of different weight and dimensions
String (8 feet in length)
Three different testing surfaces like a table, carpet or tile floor
Scale
Tape Measure/yard stick
Stop-watches (if available)
Step 1
Collect three of your school textbooks that are different size and weight (you can use books of various sizes that you have at home as well).
Step 2
Record the weight of each of the books before experimenting.
Step 3
Find three different surfaces to slide (or push) the textbooks on (examples: table, carpet, tile floor, etc.).
Step 4
Being sure not to damage the textbook, slide the textbook along various surfaces, keeping a keen eye on the frictional force that each surface has on the movement of the textbooks.
Step 5
Record the time and distance that each book traveled on the three different surfaces on your provided 49ers Frictional Force worksheet.
Stop & think
What factors do you think affect the size of the frictional force? Explore combinations such as a sliding on different sides of the textbook, on different surfaces areas, or stacking books on top of each other, or combinations thereof. Come up with some predictions on how fast and far you think the textbooks will travel.
Step 6
Tie strands of string around each textbook, and this time, pull each book and record the time it takes to pull the same distance you pushed the book on the three surfaces. Write down your observations and record the times of this experiment.
Step 7
Answer the following question: What effect would friction have on a rolling football?
Hint: Footballs are different from the books you pushed and pulled in that they have a shape that when rolled, reduces friction. You may think that footballs are immune from friction, but the surface on which they roll have a lot to do with how much friction is applied to the football. And of course, gravity has the ability to slow the football down as well.
Conclusion & reflection
By participating in this experiment, you can easily conclude that textbooks do not normally move by themselves, they have to be moved by a force. As a conclusion to this activity, reflect upon the following questions concerning the magnitude of frictional force applied on the textbooks during testing:
When you pulled the textbook towards you, you could feel a force opposing you. What force do you think is pushing against the book as you pulled it?
What happens if you double the weight by stacking one book on top of the other? How does the surface type affect the frictional force? Typically the smoother the surface is the less friction. However, sometimes tile floor, which is very smooth, will produce a large frictional force, especially if it is very clean.