- #1
AVReidy
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Homework Statement
A car accelerates uniformly from rest to a speed of 23.2 km/h in 5.4s. Find the distance it travels during this time. Answer in units of m.
Homework Equations
[itex]\Delta[/itex]x = 1/2(vi + vf)t
vf = vi + at
vf2 = vi2 + 1/2 at2
The Attempt at a Solution
I have used each one of these equations, sometimes in combination, and every time I reach the answer 1044m, which is wrong. I think the problem lies not in which equations I use, but in the way I set them up. Here's one way:
23.2km/hr = 23,200/60 = 386.7 m/s
[itex]\Delta[/itex]x = 1/2(vi + vf)t
[itex]\Delta[/itex]x = 1/2(0 + 386.7)(5.4)
I'm really stuck on this one and would really really really appreciate some help. I don't see what I'm doing wrong, because I've always arrived at the same answer (1044m) no matter which way I solve for it. This makes me think I'm using the wrong initial velocity or something like that.
Thank you so much!
Edit: I have also solved for acceleration and plugged it in. I got 71.6 m/s2. After using acceleration in one of the equations, I still got 1044m.
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