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Here is an example problem:

A sled of mass 50kg is pulled along a snow-covered, flat ground. The static coefficient of friction is 0.30, and the kinetic coefficient friction is 0.100. What force is needed to start the sled moving?

  1. What force is needed to start the sled moving?
  2. What force is needed to keep the sled moving at a constant velocity?
  3. Once the sled begins to move, what force should be applied to accelerate it at a constant rate of $2.58 m/s^{2}$ ?

I appreciate your help. I am not able to understand how to solve them, so an explanation on how to do it would help a lot.

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closed as too localized by Waffle's Crazy Peanut, David Z Dec 20 '12 at 5:23

This question is unlikely to help any future visitors; it is only relevant to a small geographic area, a specific moment in time, or an extraordinarily narrow situation that is not generally applicable to the worldwide audience of the internet. For help making this question more broadly applicable, visit the help center.If this question can be reworded to fit the rules in the help center, please edit the question.

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Hi DemCodeLines, Welcome to Physics.SE. This is a conceptual Q&A site which doesn't actually encourage users who come up with their own homework problems. Have a look at our homework policy for more FAQ. And, please don't ask several questions within a single one. If you've tried something good, we're here to help. But, this specifically asks other users to solve your problem which is definitely discouraged. If you've any sort of discussion, you could request the moderator to welcome you in chat. Good luck... –  Waffle's Crazy Peanut Dec 20 '12 at 5:08
    
And BTW, please make revisions substantial. Why did you think that $m/s^2$ and $ms^{-2}$ are different? –  Waffle's Crazy Peanut Dec 20 '12 at 5:09
    
I don't think -2 is same as 2. –  Ash Ketchum Dec 20 '12 at 5:10
    
Ok, Let's see what other users believe till now. Could we? –  Waffle's Crazy Peanut Dec 20 '12 at 5:11
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@DemCodeLines I appreciate you coming and checking the site out, but this is really not a homework help site. It's more for conceptual physics questions. As you've seen, we can offer some help with this sort of thing in Physics Chat, and you can also try the homework help section of Physics Forums –  David Z Dec 20 '12 at 5:30