Ball dropped from building - find speed and kinetic energy

Click For Summary

Homework Help Overview

The problem involves a mass dropped from a height, specifically a 0.50kg ball dropped from a 20m tall building. Participants are tasked with finding the speed of the ball just before impact and the kinetic energy at the halfway point of the fall.

Discussion Character

  • Exploratory, Mathematical reasoning

Approaches and Questions Raised

  • Participants discuss conservation principles and relevant equations. One participant attempts to calculate the final speed using a formula involving gravitational acceleration and height. Another participant questions the correctness of their calculations for kinetic energy.

Discussion Status

The discussion is active, with participants providing feedback on each other's calculations. Some guidance has been offered regarding the use of speed in kinetic energy calculations, but there is no explicit consensus on the final answers.

Contextual Notes

Participants are working under the constraints of a homework assignment, which may limit the information they can use or the methods they can apply.

NewJersey
Messages
35
Reaction score
0
An 0.50kg mass is droped from the top of a 20m tall building. Immediately before hitting the sidewalk

a) the speed of the ball is ?
b) The KE of the ball half way down will be


Help??
 
Physics news on Phys.org
What's being conserved here, and what equation should you use? Any thoughts?
 
Basically right now I am at this point
vf= (2*9.8* 20) the sqaure root of this answer .

Would that tell me the final speed
 
Yes, that is correct.
 
So for part b

vf= 2*9.8*10 and the sqaure root of this
= 14

Is this part right.
 
Well, that is the speed that you would plug into the equation for kinetic energy, but yes, you are correct.
 

Similar threads

Replies
1
Views
2K
Replies
7
Views
3K
  • · Replies 21 ·
Replies
21
Views
5K
  • · Replies 6 ·
Replies
6
Views
3K
  • · Replies 32 ·
2
Replies
32
Views
4K
  • · Replies 4 ·
Replies
4
Views
2K
  • · Replies 6 ·
Replies
6
Views
2K
  • · Replies 10 ·
Replies
10
Views
3K
  • · Replies 7 ·
Replies
7
Views
5K