Work-kinetic energy issue

  • Thread starter Spock007
  • Start date
  • #1
1
0
Assume a situation that there is a ball on the ground. A vertical force is applied to raise the ball to h at a constant speed. According to work-kinetic energy theorem, no net work is done on the ball owing to the constant speed. However, the potential energy increases as the ball gains elevation. The total energy does not seem conservative in this case. Why?
 
Last edited:

Answers and Replies

  • #2
Simon Bridge
Science Advisor
Homework Helper
17,874
1,657
Welcome to PF;
The work-KE theorem you have been taught is wrong in general and can only be used in specific circumstances.
More completely, the work done on an object is equal to the change in it's mechanical energy. In this case: ##W=\Delta K + \Delta U##
 

Related Threads on Work-kinetic energy issue

  • Last Post
Replies
2
Views
1K
  • Last Post
Replies
13
Views
3K
  • Last Post
Replies
8
Views
868
Replies
2
Views
2K
  • Last Post
Replies
4
Views
2K
  • Last Post
Replies
14
Views
1K
  • Last Post
Replies
1
Views
831
  • Last Post
Replies
2
Views
847
Replies
10
Views
91K
  • Last Post
Replies
17
Views
4K
Top