Finding initial velocity given displacement, time, and final velocity

In summary, the conversation discusses a woman running at a constant velocity and then accelerating uniformly to the west. It is mentioned that she runs 253 m west in 6.12 seconds and ends up with a velocity of 5.05 m/s. The question is how fast was she originally going and what would her average velocity have been if she had run the same distance in 5.50 seconds. The equations vf = vi + at and v = (xf - xi)/t are mentioned, but the attempt at a solution is not clear. The correct answer for the average velocity during the acceleration is 41.34 m/s, which seems unlikely given the initial and final velocities provided.
  • #1
dudelol
1
0

Homework Statement


A woman running at constant velocity speeds up and accelerates uniformly to the west by running 253 m west in 6.12 s. ff she ends up getting up to a velocity of 5.05 m/s w, how fast was she going originally? If she had run the same disance in 5.50 s, what would her average velocity have been during her acceleration?
vf = final velocity = 5.5m/s
x = displacement = 253m
t = 6.12 s
find vi?

Homework Equations


vf=vi+at
v=(xf-xi)/t

The Attempt at a Solution


I honestly am stumped on this question.
average velocity during the acceleration 253/6.12 =41.34 m/s
 
Physics news on Phys.org
  • #2
This woman would be running at like 100 miles per hour, and then the problem says she ends up "getting up to" a velocity of 5.05 m/s. Something's wrong here.
 

1. How do you calculate initial velocity with displacement, time, and final velocity given?

To calculate initial velocity, you can use the formula v0 = (vf - d)/t, where v0 represents initial velocity, vf represents final velocity, d represents displacement, and t represents time.

2. Can initial velocity be negative?

Yes, initial velocity can be negative. It simply indicates that the object is moving in the opposite direction of the positive direction defined in the given problem.

3. Is it possible to find initial velocity without knowing the final velocity?

Yes, it is possible to find initial velocity without knowing the final velocity. In this case, you can use the formula v0 = d/t, where v0 represents initial velocity, d represents displacement, and t represents time.

4. How do you find the initial velocity of an object thrown vertically?

To find the initial velocity of an object thrown vertically, you can use the formula v0 = √(vf2 - 2gh), where v0 represents initial velocity, vf represents final velocity (which is usually 0 for an object thrown vertically), g represents the acceleration due to gravity (9.8 m/s2), and h represents the height the object was thrown from.

5. Can you use the same formula to find initial velocity for objects with different acceleration?

No, the formula for finding initial velocity with displacement, time, and final velocity is only applicable for objects with constant acceleration. For objects with different acceleration, you would need to use a different formula or method to find the initial velocity.

Similar threads

  • Introductory Physics Homework Help
Replies
17
Views
1K
  • Introductory Physics Homework Help
Replies
3
Views
696
  • Introductory Physics Homework Help
Replies
8
Views
1K
  • Introductory Physics Homework Help
Replies
5
Views
1K
  • Introductory Physics Homework Help
Replies
17
Views
782
  • Introductory Physics Homework Help
Replies
1
Views
988
  • Introductory Physics Homework Help
Replies
5
Views
997
  • Introductory Physics Homework Help
Replies
5
Views
912
  • Introductory Physics Homework Help
Replies
5
Views
963
  • Introductory Physics Homework Help
Replies
3
Views
2K
Back
Top