Motion in one dimension

  • #1
when we throw an object upwards why the time of descent is greater rhan time of ascent?
 

Answers and Replies

  • #2
hilbert2
Science Advisor
Insights Author
Gold Member
1,525
545
It's not.

The object's descent is just a time-reversed ascent, because total energy is conserved.
 
  • #3
Nugatory
Mentor
13,453
6,488
when we throw an object upwards why the time of descent is greater rhan time of ascent?

What specific situation are you considering? In general, the two times will be about the same, with any difference being caused by air resistance acting differently on the ascent and the descent.
 
  • #4
in case we consider air resistance
 
  • #5
HallsofIvy
Science Advisor
Homework Helper
41,847
965
in case we consider air resistance
Don't you think it would have been a good idea to tell us that initially?

The speed coming down will be less than the speed going up because the potential energy will be the same at the same height but the total energy will be less because of energy lost to air resitance. So kinetic energy will be less at the same height coming down than going up.
 
  • Like
Likes 1 person
  • #6
Nugatory
Mentor
13,453
6,488
in case we consider air resistance

Even then, the details matter. A dense sphere (think cannonball) with an initial speed of a few tens of meters per second will not be measurably affected by air resistance - and this is also the problem you'll most often encountered in introductory physics classes. On the other hand, a spin-stabilized projectile that tumbles on the the way down, or a projectile whose initial velocity exceeds its terminal velocity in air will behave very differently on ascent and descent.
 

Related Threads on Motion in one dimension

  • Last Post
Replies
8
Views
9K
A
Replies
1
Views
3K
Replies
18
Views
1K
  • Last Post
Replies
2
Views
2K
  • Last Post
Replies
3
Views
5K
P
Replies
4
Views
4K
Replies
6
Views
1K
Replies
5
Views
2K
  • Last Post
Replies
1
Views
8K
  • Last Post
Replies
23
Views
1K
Top