• Support PF! Buy your school textbooks, materials and every day products Here!

Is Work done when there is constant velocity?

  • Thread starter ericka141
  • Start date
  • #1
8
0

Homework Statement


"You carry your 14.0 kg bag of textbooks horizontally 1.8 m above the ground, at constant velocity for a distance of 25 m. Ignore wind resistance. How much work do you do on the bag in the process?"

Homework Equations


W=Fd
F=ma


The Attempt at a Solution


If work equals force times distance, and force is equal to mass times acceleration, wouldn't the whole thing equal zero because of the constant velocity = no acceleration?
 

Answers and Replies

  • #2
Doc Al
Mentor
44,904
1,169
If work equals force times distance, and force is equal to mass times acceleration, wouldn't the whole thing equal zero because of the constant velocity = no acceleration?
The net force on the bag is zero. But what force do you exert and what work does that force do?
 
  • #3
662
307
....If work equals force times distance....
W=∫F.ds
use that along with what Doc Al suggested.
:wink:
 
  • #4
8
0
So is there only work being done in the vertical direction, aka. the force is takes you to physically hold the bag up?
 
  • #5
662
307
If there's displacement in that direction, yes. Work is proportional to displacement.
 

Related Threads on Is Work done when there is constant velocity?

  • Last Post
Replies
8
Views
1K
Replies
2
Views
6K
Replies
7
Views
3K
  • Last Post
Replies
1
Views
1K
  • Last Post
Replies
6
Views
2K
  • Last Post
Replies
5
Views
7K
  • Last Post
Replies
3
Views
2K
  • Last Post
Replies
7
Views
8K
  • Last Post
Replies
2
Views
2K
Replies
5
Views
541
Top