Super congfused about finding distance with constant acceleration

Click For Summary

Homework Help Overview

The discussion revolves around a kinematics problem involving a car accelerating from rest and traveling a certain distance over a specified time. The original poster is trying to determine the distance traveled in the first part of the journey given the total distance and time.

Discussion Character

  • Exploratory, Conceptual clarification, Mathematical reasoning, Problem interpretation

Approaches and Questions Raised

  • The original poster attempts to calculate average velocity and distance using basic formulas but encounters confusion regarding the application of kinematic equations. Some participants suggest using specific kinematic equations for constant acceleration and question the correct interpretation of variables involved.

Discussion Status

Participants are actively discussing various approaches to solve the problem, with some providing guidance on which equations might be relevant. There is a recognition of the need to clarify the use of initial and final velocities in the context of the equations being considered.

Contextual Notes

There is some uncertainty regarding the wording of the problem and how to graph the values involved. The original poster expresses difficulty in applying the kinematic equations due to the initial conditions and the need for further clarification on the setup.

Butterfly30
Messages
28
Reaction score
0
*confused

A car speeding up from rest to constant accel. travels 100 meters in 6.04s. How far did it travel in the first 2.37 seconds?

So I figure if I divide distance by time 100/6.04 it will give me the velocity 16.5m/s. And since distance = vt I would do d=15.6*2.37 which equals 37.03m but this is wrong. I was also told to try drawing a graph of velocity vs time...but how can I graph numbers such as these (high and low #'s with decimals) If I can't graph it I can't find the slope or y intercept...so I'm lost
 
Last edited:
Physics news on Phys.org
The car is accelerating at a constant rate (if I understand the problem correctly, it's wording is strange), so its velocity is constantly changing.

Do you know any kinematic equations for motion under constant acceleration?
 
In class we've used these: v=v0+at, x=x0+v0t+1/2at^2, and v^2=V0+2a(x-x0)
but from what I see I have an intitial velocity of 0, a distance and starting point which would be x0=0 and x=100m then I have two times... I'm having trouble fitting this all in..
 
Start by using [itex]x - x_o = v_{o}t + \frac{1}{2}at^2[/itex] to find this acceleration, which is a constant value.
 
Can I use the eqtn v=v0+at instead with the initial velocity being zero, velocity being 100m/6.04s and t=6.04s? and solving for a?

and them plug it into the x-x0 eqtn?
 
Last edited:
Butterfly30 said:
Can I use the eqtn v=v0+at instead with the initial velocity being zero, velocity being 100m/6.04s and t=6.04s? and solving for a?

No. The v in that equation is final velocity. You would be using average velocity. Do what CAF123 suggests.
 
Ok so when I solve for a the eqtn is a=2x/t^2. Then I plug a back into the eqtn but I use the second given time... Am I on the right track?
 
Butterfly30 said:
Ok so when I solve for a the eqtn is a=2x/t^2. Then I plug a back into the eqtn but I use the second given time... Am I on the right track?
Yes!
 

Similar threads

Replies
1
Views
1K
  • · Replies 6 ·
Replies
6
Views
1K
  • · Replies 5 ·
Replies
5
Views
1K
  • · Replies 5 ·
Replies
5
Views
3K
  • · Replies 11 ·
Replies
11
Views
3K
  • · Replies 6 ·
Replies
6
Views
2K
  • · Replies 2 ·
Replies
2
Views
5K
Replies
15
Views
3K
  • · Replies 8 ·
Replies
8
Views
4K
Replies
12
Views
2K