# I have a problem with acceleration,please help~

**URL:** <https://forum.makecode.com/t/i-have-a-problem-with-acceleration-please-help/210>\
**Category:** Arcade\
**Created:** [May 29, 2019, 6:11am UTC](https://forum.makecode.com/t/i-have-a-problem-with-acceleration-please-help/210 "2019-05-29T06:11:31Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![hogan](https://sea2.discourse-cdn.com/flex020/user_avatar/forum.makecode.com/hogan/32/17525_2.png) [@hogan](https://forum.makecode.com/u/hogan)\
**Post date:** [May 29, 2019, 6:11am UTC](https://forum.makecode.com/t/i-have-a-problem-with-acceleration-please-help/210/1 "2019-05-29T06:11:31Z")

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> **[test acceleration](https://arcade.makecode.com/68665-87172-15521-78552)**
>
> Made with ❤️ in MakeCode Arcade.

  
I have a doubt， about the acceleration，please refer to my program for details…  
According to the physical formula： v^2 - v0^2 = 2ax  
In the program I set the acceleration to 200, the speed is -100, so the moving distance should be 25，but it just 20. After that， I tried multiple sets of data and found that there is a coefficient of 0.8.  
is this a bug or sth else？  
thank u ~

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<div class="post-metadata">

**Author:** ![hogan](https://sea2.discourse-cdn.com/flex020/user_avatar/forum.makecode.com/hogan/32/17525_2.png) [@hogan](https://forum.makecode.com/u/hogan)\
**Post date:** [May 29, 2019, 6:26am UTC](https://forum.makecode.com/t/i-have-a-problem-with-acceleration-please-help/210/2 "2019-05-29T06:26:10Z")

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Then I tried it in the beta. there are still some errors.  
According to the set value, its coordinates at the highest point should be 47, but it went to 45

I think it is perfect to multiply the acceleration by a factor of 0.8 on the basis of version 0.8.11