Khan/khan-exercises — Issue #4443: Kinematic equations - 2 sollutions
Author: KhanBugz
Created: 2011-10-17 00:43:30+00:00
State: open
Labels: ie8, vista

Reporter: j.hx@hotmail.com

Kinematic equations

Given:
d = -786.83 m
vf = -101.72 m/s
a = -6.4 m/s2

Asked:
t = ?
(vi = ?)

Sollution:
It seems to me there are 2 possible sollutions here...

A positive vi of 16.6 m/s with t = 16.6 s
and a negative vi of -16.6 m/s with t = 13.3 s.

However... the website only accepts one answer as being correct...

[kinematic_equations.html?seed=128&problem=0](http://sandcastle.khanacademy.org/media/castles/Khan:master/exercises/kinematic_equations.html?seed=128&problem=0&debug)

[]

Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 6.0; Trident/4.0; GTB7.1; SLCC1; .NET CLR 2.0.50727; Media Center PC 5.0; .NET4.0C; .NET CLR 3.0.30729; AskTbMP3DS/5.12.2.16749; .NET CLR 3.5.30729)

MathJax is loaded, ready, queue length: 0