Volume of a square using cross section

Click For Summary
To find the volume of the area bounded by y=x^2 and y=9 with cross sections perpendicular to the y-axis, first sketch the graphs to visualize the region. The correct approach involves using the formula for the area of the cross section, which is (9 - y)², and integrating with respect to y. The integration limits should be from 0 to 9, as these represent the y-values where the curves intersect. The integral will yield the volume of the solid formed by these cross sections. Understanding the orientation of the cross sections is crucial for setting up the integral correctly.
mikaloveskero
Messages
6
Reaction score
0

Homework Statement


What is the volume if the area bounded by y=x^2 and y=9 and the cross sections are perpendicular to the y axis


Homework Equations





The Attempt at a Solution


I have no idea
 
Physics news on Phys.org
At least draw the graph and make an attempt. Take a picture of it or scan it or just draw it in some picture editor and attach it to your post.
 
I drew the picture and y=9 is the higher graph and y=x^2 is the lower graph. So from there do you do (9-x^2)^2 and take the integral from -3 to 3 ?
 
The cross sections are perpendicular to the y-axis, not parallel. So the integral will be with respect to y, not x.
 
Question: A clock's minute hand has length 4 and its hour hand has length 3. What is the distance between the tips at the moment when it is increasing most rapidly?(Putnam Exam Question) Answer: Making assumption that both the hands moves at constant angular velocities, the answer is ## \sqrt{7} .## But don't you think this assumption is somewhat doubtful and wrong?

Similar threads

  • · Replies 4 ·
Replies
4
Views
1K
  • · Replies 10 ·
Replies
10
Views
2K
Replies
3
Views
2K
Replies
2
Views
1K
Replies
2
Views
3K
Replies
6
Views
4K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 4 ·
Replies
4
Views
4K
  • · Replies 5 ·
Replies
5
Views
4K
  • · Replies 2 ·
Replies
2
Views
2K