How Do You Calculate the Maximum Height of an Object Thrown Upward?

In summary, the conversation discusses how to determine the maximum height of an object thrown vertically upward with an initial speed of 21 m/s. The suggested approach is to reframe the problem and use a kinematic equation to solve for the height. The key points of interest are the initial point, a midpoint where the object reaches two thirds of its maximum height, and the top point where the object comes to rest. It is suggested to use the distance between the midpoint and the top point, which is h/3, to apply the kinematic equation and find the maximum height.
  • #1
finlejb
14
0
An object is thrown vertically upward such that it has a speed of 21 m/s when it reaches two thirds of its maximum height above the launch point. Determine this maximum height.

I can't figure what to do since initial velocity isn't given and I don't see a way to solve for it.
 
Physics news on Phys.org
  • #2
Reframe the problem this way: An object is thrown upward with an initial speed of 21 m/s and rises to a height of h/3. Solve for h.
 
  • #3
Oh I like that suggestion Doc Al. Very clever.

I would use a kinematic equation to help get your answer... this one perhaps?

[tex]v_{f}^2=v_{i}^2+2ad[/tex]
 
  • #4
That equation doesn't really help me though, Jameson. It has two variables in it that I don't know the value of.

And I kind of see where you're going, Doc Al, but why h/3? It seems like 2h/3 would be what I'd want to solve for...
 
  • #5
What doc al is saying is you can find the maximum heigth because at the point [itex]\frac{2}{3}h[/itex] the initial velocity would be 21ms/2 and at maximum height (which is [itex]\frac{1}{3}h[/itex] above that point) you know the ball would come to rest. This would allow you to use Jameson's equation to calculate the maximum height.
 
  • #6
finlejb said:
And I kind of see where you're going, Doc Al, but why h/3? It seems like 2h/3 would be what I'd want to solve for...
Hootenanny already explained it, but let me put it this way. You have three points of interest:
(1) start: y = 0; v = ?
(2) "mid" point: y = 2h/3; v = 21 m/s
(3) top: y = h; v = 0 m/s

What I'm suggesting is that between points 2 & 3 the object travels a distance of h/3. A perfect opportunity to apply Jameson's kinematic equation.
 

Related to How Do You Calculate the Maximum Height of an Object Thrown Upward?

1. How can I prepare for a test tomorrow?

The best way to prepare for a test is to review your notes and any study materials provided by your teacher. Make sure you understand the key concepts and practice solving similar problems.

2. I can't figure out this problem, what should I do?

If you are having trouble with a specific problem, try breaking it down into smaller parts and see if you can solve each part individually. You can also ask for help from your teacher or classmates.

3. What if I don't have enough time to study before the test tomorrow?

If you are short on time, focus on reviewing the most important concepts and practicing problems that you struggle with the most. Don't try to cram too much information in a short amount of time, as it may cause more confusion.

4. How can I stay calm and focused during the test tomorrow?

To stay calm and focused during the test, make sure you get a good night's rest, eat a nutritious breakfast, and arrive at the test location early. Take deep breaths and don't panic if you encounter a difficult problem - skip it and come back to it later if you have time.

5. What if I fail tomorrow's test?

If you don't do well on tomorrow's test, don't beat yourself up. Use it as a learning experience and try to identify what went wrong. Talk to your teacher to see if there are any extra credit opportunities or make a plan to improve for future tests.

Similar threads

  • Introductory Physics Homework Help
2
Replies
38
Views
1K
  • Introductory Physics Homework Help
Replies
4
Views
1K
  • Introductory Physics Homework Help
Replies
14
Views
2K
  • Introductory Physics Homework Help
Replies
3
Views
243
  • Introductory Physics Homework Help
Replies
1
Views
959
  • Introductory Physics Homework Help
Replies
3
Views
1K
  • Introductory Physics Homework Help
Replies
2
Views
3K
  • Introductory Physics Homework Help
Replies
9
Views
5K
  • Introductory Physics Homework Help
Replies
7
Views
2K
  • Introductory Physics Homework Help
Replies
6
Views
994
Back
Top