# Kinematics - Non constant acceleration [closed]

A biker traveling the road is 100 km away from his destination, at t=0 (initial time). His speed, at the start point, is 100km/hour, and varies equalys to his distance from the final destination, decreasing. So, after 40 km traveled(and therefore 60 km away from his target) he is at 60 km/h. H

How much time will it take until he reaches his destination? What is the function that express the position of the biker?

I think this might help: http://hyperphysics.phy-astr.gsu.edu/hbase/avari.html

EDIT: That is NOT a homework assignment. I created this question in my head.

So, i worked a little, and find the following equations:

V = -s + 100

Since ds/dt = velocity , => ds/dt = (-s+100) ds/(-s+100) = dt

ln 100 - ln (100 - s)

So, how i find the equation of acceleration? thats the real question.

## closed as off-topic by David Z♦Mar 23 '16 at 15:37

This question appears to be off-topic. The users who voted to close gave this specific reason:

• "Homework-like questions should ask about a specific physics concept and show some effort to work through the problem. We want our questions to be useful to the broader community, and to future users. See our meta site for more guidance on how to edit your question to make it better" – David Z
If this question can be reworded to fit the rules in the help center, please edit the question.

• HINT:- make an equation and then find derivative! – user5954246 Mar 23 '16 at 15:43
• Please take a minute and read the meta site. The homework tag is not just for homework questions, but for exercises similar to homework that require basic calculations and no physical concepts. – Martin Mar 23 '16 at 18:23